I am conceited yet insecure, help?

In the past I have been bullied, I used to be very funny looking and had low self esteem. I was a ' mommy's little girl' I have been a' bully'- i eventually got tired of getting picked on so I changed the way I looked and started picking on people who were' less attractive' than i . Now in high school I feel i have found a way to balance myself, at least in public. I feel bad though, everybody thinks im so nice and helpful, but the only way i can keep up the 'nice' is by constantly reminding myself of how much lower everyone else is.. it keeps me going. At the same time I am vrey insecure, I look at my reflection constantly, it just bugs me, I draw, and it bugs me that I am not as beautiful as my drawings... People say I have great style and all, but that style is just my attempt at trying to mimic the beautiful people of my artwork. So many people tell me I am attractive, I do not believe them, somethimes i look in the mirror and feel beautiful, other times i feel like a monster, :( I am going to college soon, and I am just having a hard time with my identity. Oh, god, now I have braces, that''s only made things worse. I want to be a genuinely good person, and i want to love myself without having to put others down , inside my mind. I feel like such a fake. I am a fake.