Oh Poc. *BIG HUG* (you're totally brining out the empathetic girl in me...and making me late to class, hehe)
I understand questioning. I think it's pretty common. My asexual friend and I have had many conversations where we talk about the fear of making it all up, that we went through so much emotional crap and took other people with us, and maybe we were just doing it for attention or something silly like that. Right now I'm also in another weird phase, where I don't want to be bi or trans, or geeky or tall or anything weird. I want to be very normal, because it's simpler.
So yes, while you may be doing this for other people, I can understand doing it. Just be honest with yourself (I know, you've heard that). After you've done the girl thing for awhile, make yourself think about how it's made you feel, with no thoughts for other people. Even if you have to slow things down for other people, the final form you chose has to be based on you.
Between now and then, just have fun. When it gets to you, view it as a dress up game. When it gets to you more, wear a tie. Or spit. I like to spit, and throw things off balconys. If you ever need someone to talk to, I'm always willing to play big sister/brother. All my little brother ever does is yell at me and steal the car, or mope around the house (he's 18 going on 15), so I'd be glad of a change.
Hope things get easier for you. I'll be thinking happy thoughts for ya.