JessM. is totally right. Transitioning is a no-win scenario for a couple - at least if you define "win" as "staying together as a man and a wife."
The important thing to think of is your child, and you need to take care of yourself so that you can take care of her.
Whatever happens, your wife will get over it. Your child? If you totally break down, or do something really desperate and kill yourself, your kid won't recover well from that. Not at all. Yeah, it will suck for your wife no matter what you do. (Stay as you are? She has to live with your miserable ass, or bail if she can't take it. Transition - yeah, she gets to live with a woman, or bail, if she can't handle it. Die? Yeah, she'll get over it. That's the worst - but spouses recover from this.)
As for you, transitioning is hard. You get everything you want? How can that be a "lose"? Yes, you get to live an authentic life. You also get to experience prejudice that you've almost certainly never experienced in your life. Depending on your situation and luck, this can either be no big deal, or incredibly challenging. (But trust me - even if you are VERY privileged, you'll experience some of this.)
Your mutual "win" needs to be having the best life you can have for your child, given the limitations of your situation. Her individual "win" is to move on with her life. Yours is to live the best life you can as your true self, and to be there for your daughter.
It's a tough break for everyone, hon.
