Don't ever let anyone tell you you aren't pretty! I think all you need is a little confidence. And when you cosplay, make-up is your friend and can make you look like a whole new person.
But just with your hair and your skin, I could see you as Esmeralda in the Hunchback of Notre Dame. You wouldn't even need a wig really unless you wanted to go with a solid black one. She's got some bigger hair and yours looks like it could go big!