Grey Matter has some really good advice already, I just want to chime in though. You really are a girl, regardless of what anyone else or even your body says. I can relate a bit to you in that I was abused like that when I was a little kid too. I'm coming from the other side of the same coin, I've always felt like a boy trapped in a female body. My family is also not supportive of this, but there are people out there who are and who can help you out, even if just someone to talk with. Maybe see if there's a trans* or trans friendly community near you?