Taielyn,
It's very hard for you as a woman to understand how hard it is for a man to be a cross-dresser (or transgender), let alone tell someone he really loves, that he is a cross-dresser. Keep in mind that there is a spectrum of gender identity usually rated 1-6 with 1 being cis-gender, 2 being a fetish dresser, 3 being a cross-dresser, 4 being a public cross-dresser, 5 wanting to transition but not critical, and 6 is the "Transition or die" group.
Boys who are feminine growing up are often brutally assaulted on a regular basis, often starting as young as 5 years old, and often by large groups of 10-15 boys at a time. Imagine going to school every day, knowing that you would have 10-15 boys hitting you before school, kicking you during recess, kicking and hitting you during gym, and then beating you with sticks on the way home. Usually there are names that go with these beatings like "Sissy", "Fairy", and far worse. Often feminine boys are beaten because they are attractive to some boys who don't want to admit that they are attracted to a boy, no matter how feminine. Other boys participate in the assault because if they don't, they will be targeted as well.
Many of us have told girlfriends or girl friends too soon and have been seriously hurt. What was a closely guarded secret becomes gossip and spreads like wild-fire, which leads to more violence. In other cases, a serious love interest may not only reject us, but may also spread false information, such as that we are gay, that we like boys, or worse. This can often lead to more dire consequences. So the fact that he told you a secret he has kept for many years, possibly a decade or more, is a pretty good sign that he loves you so much he can barely imagine life without you. But he can't live a lie either. He has literally put his life on the line for you.
Being transgender is not a "phase", a "fantasy", or a "delusion". Often there are true medical reasons for these feelings, including the actual makeup of the brain. There are some boys who have female skeletal structure, facial structure, mannerisms, and a few may even have female body parts or missing or deformed boy body parts. The medical condition is "Gender Ambiguity" and is commonly referred to as Intersex. Being intersex does not mandate being transgender, and vice-versa, but they are very often related.
You boyfriend sounds like he's fairly low on the spectrum. He may be quite content to limit his dressing to home, with or without you. Keep in mind that this may be where his more intimate, sensitive, caring, and sensitive nature have to live.
The thing you need to look at is your attraction to him. There is a very good chance that you were actually attracted to many of his feminine traits. Many women are attracted to feminine or males because they are more sensitive, caring, they listen better, they are more romantic, they enjoy kissing and cuddling more, and more willing to let the woman take control or make requests. Often the women who are attracted to these males are very strong, secure, confident, and powerful women who have no trouble leading teams, managing others, and getting what they want. To a feminine man, these are traits that make you attractive to him. The fact that you made him see a counselor and he did it with very little argument indicates how much he cares, and also demonstrates your power and his desire for you to have that power.
You refer to implants, which suggests that you are not well informed about this world at all, and are probably just now starting to find out about the subject. Cross-dressers often have the desire to fully present as female, to look like they actually are female. To do this, they may use breast forms. These can range from home made "fillers" such as bags of rice or beans, to foam, to forms made of a gel that is quite realistic. Forms can range in price for free (rice bags) to $10 "silicone bra" at WalMart to $300 forms that can be attached for several days in a row.
It is unethical for a therapist, such as a CSW or PhD psychologist to try and force or convince a transgender client to accept their birth gender and stop the dressing. The reason for this is that it can push them deeper into secrecy, trigger depression, actually make their gender dysphoria more intense, and could even lead to suicide.
If your boyfriend wanted to transition (actually become a woman), he would be required to do the "Real Life Test", which means living as the chosen gender as much as possible for at least a year, then starting hormones and living full-time as female, and legally changing name and gender. Some will decide not to have the Gender Reassignment Surgery (GRS), but will continue to live as female the rest of their lives. At this point, it does not seem that your boyfriend is headed in this direction.
You should find a counselor with with solid experience in working with Gender Dysphoria. He will probably go to around 5-8 sessions, first in male form, then perhaps in female form, and at that point, you will see the counselor together. The counselor may wish to see you alone a few times as well.
The real challenge is not getting him to stop, but deciding how the two of you will relate to the girl side of him. One option may be to let him explore this in private, at home, when you are not there. This means that you will need to schedule 3-4 days a week when you will not be there and he will. Some men take jobs where they "go on the road" and indulge when they are at hotels. This can be very hard on a relationship because it can be experienced as rejection of something that is very important to your partner. Imagine if your boyfriend insisted that you wear mid-thigh miniskirts, dark hose, 3 inch heels, low cut satin shirts, and hair styled the way he liked it, as well as full make-up every day, and if you didn't appear that way, he would ignore or avoid you, or worse start to criticize everything about you. It wouldn't take long for him to turn your love into hate, and you would be gone.
Another option is for him to dress with you, in the house, in private. You may even find that he is willing to do chores you don't like doing, like cooking, cleaning, dusting, or vacuuming, even cleaning the bathrooms. You may also find that SHE knows exactly where to scratch your back, can kiss your neck in a way that covers your whole body with goose bumps.
I've been married twice. The first time, I told my ex about being a cross-dresser about 3 weeks after we moved in. She seemed to accept so I proposed and we got married about 6 months later. Even before the wedding there were indications that she wasn't as accepting as she pretended. Over the next 8 years, it reached the point where I would work absurdly late, often well after midnight, and spend 12-15 hours a day at work to avoid the rejection and snarky remarks. We finally went to a couples counselor and she immediately brought up my "Wardrobe Problem". We talked about it together for a few weeks, then he met with us separately.
With me, the counselor asked a lot of questions to assess my true gender identity. I told him that I had started dressing when I was 6, because most of my friends were girls and we were just trading clothes. When a mother freaked out and demanded that I be banned from playing with the girls, I got severely beaten by the boys on a regular basis. Even without dressing up, it was nearly impossible to hide my feminine nature. How I laughed, how I covered my mouth when I laughed, how I would squeal with delight, or giggle, how I would often use a whole octave in a single sentence. My hips were wider, my waist was smaller, and my chest was bigger than most boys my age. I was tall, but thin and had very long legs. Finding pants was always a challenge. If I wore boys pants, I had to pay extra to get the 36 inch inseam, I would use a belt to gather up all the extra space at the waist, and I'd wear dress shirts that fit like tents to hide my curves. I often wore jackets. At puberty, when I found out I had a bass voice I turned to drugs and booze and nearly killed myself numerous times.
With my ex, he asked what she found attractive about me, then has he tried to point out that these were feminine traits, she kept saying she couldn't stand the way I looked. She actually LIKED the feminine traits, but wanted me hairy and masculine looking and dressing like a man all the time.
Ultimately, he brought us together said "Rex/Debbie is transsexual and should transition as soon as possible, I'm surprised he has lived this long", then "Leslie is not bisexual or a lesbian and will never be attracted to Rex as long as he continues to look so feminine. The communication is great, the love is there, and you support each other, but this conflict can't be resolved. Your options are 1 - Continue your platonic marriage (we hadn't had sex in over 2 years), 2 - Have an open marriage where you each take your own lovers but stay married, or 3 - Get divorced and see if you can marry someone who is a better match. I chose option 1, she chose option 2, but after about 4 months, her lover wanted to get married so we ended up with option 3.
When I married Lee, my current wife, I was much more honest much earlier. I met her on match.com where my profile contained pictures of Debbie as well as Rex. Lee sent a note saynig "Yo, you're wearing a dress, what's that about?". I sent her a response explaining that I was transgender and had wanted to transition, but felt I was too old and fat to do so at this point in my life. We talked on the phone for 2 weeks, then went out on a date. When I met her parents I realized she had great role models and could be a great wife. When she lost the keys to our beach rental, I was so calm and so supportive she decided I was a keeper. She realized that was my feminine nature coming out. I didn't freak out, I just asked if she wanted me to book a hotel nearby, go back to my place (closest), or sleep in the car. She opted to sleep in the car, and we cuddled together. I just wanted to make sure she was taken care of.
Fast forward about 6 years, including a wedding, a stroke (mine), 8 hernias (hers), and lots of love, and the death of my father created the space where I wanted to transition. I started seeing a therapist, and was looking at boot-leg hormones, and Lee said "I'm not OK with this". I sorta freaked out. I was in Maine and had mixed a "Prestone Cocktail" before I poured it down the drain and when I got back to NJ I told my doctor I needed help. A few days later I started seeing a gender counselor, and after about 5 sessions, Lee came along. We started going ot dinner as Debbie and Lee, and Lee helped me to dress like a professional business woman. It was a bit like an episode of "What not to wear" with all my "club wear" going into the trash, and then having to buy longer skirts, looser tops, jackets, and business appropriate shoes. At the same time, Lee was beginning to see how much happier I was. I even looked about 15 years younger. I had a mild heart problem, and shortly after that I was approved for spiro and estro. When I told my heart doctor what I was taking, he said "Wonderful, Now I can take you off those really dangerous drugs I was giving you, most men hate the side effects, but you don't seem to mind".
Today I have been living as Debbie full time for about 3 years now, and have legally changed my name and gender. I even work as Debbie. Lee and I are closer than ever, and happier too. I don't think I have ever loved as much or experienced the love of others as much. It's so much easier to experience love when I don't have to pretend not to be what I am and pretend to be what I am not. I wasn't even very good at it.. Her family likes Debbie even better than Rex, as do the people at work, and even the people at church. Again, it's so much easier when you aren't hold up a clown mask to survive.
Given what you have written in your original post, it's pretty obvious that you are very much in love with both the boy and the girl, but you are still struggling with how to deal with the wardrobe issue. The good news is that he seems to like being a man, with it's special privileges, benefits, and conventions, and seems to only need to let the girl out on occasion, rather than 24/7.
As for coming home with a boyfriend, if he were attracted to guys, he would have been searching out guys. He may find your strong personality, positive outlook, power, and confidence to be very attractive, even though these are "masculine" traits. I tell Lee, "You are more than man enough, and more than woman enough, for me, and I love you just the way you are, no matter what changes". I've always been a bit bisexual, but boys/men were also associated with violence and pain. Even if I got a wonderfully romantic offer, I would never want to jeopardize the wonderful relationship I have with Lee. I suspect your boyfriend is similar, he wants you and cares enough to share a secret he might have taken to the grave if you hadn't found his stash.