How to be confident?

I feel like the ugliest person in the world.  My teeth aren't straight, I don't have a flat belly, my skin isn't clear.. 
My boyfriend tells me i'm pretty but i see him all the time checking out the girls with blonde hair, blue/green eyes, big boobs, perfect smile and straight hair..And that makes me feel so much worse about myself. I'm none of that. I have really curly hair, daek brown eyes, red/brown hair.. I suffered from depression from ages 8-14 and i was bullied every day and told to kill myself because i'm ugly. I feel like i cant have a good relationship all because i'm too jealous because i don't feel good enough...
What can I do?