I did it!
I finally found the courage to come out at my school. It wasn't all that difficult, since the school staff already knew, but I guess I just had to find the right time to just let everyone else know. I figured that since I'm now wearing a bra (I got a sports bra because it was getting a little uncomfortable otherwise), people might start asking awkward questions if they noticed. To avoid that, I just answered the question en masse before it was asked.
Now I feel so much better; mainly because I won't be called by my male name all day long. It was the last place (other than the rare phone calls with mom) that I heard that name, so now I can be through with it. My first class today was particularly bad about this, because there's a guy in the class named Jesse and I almost always turned my head when I heard that name. I also stopped automatically recognizing my male name when I was called on. Now everyone will just call me Jessica and I can be rid of that confusion.