I'm really jealous of my "friend"?

So, well I don't really have a social life, I'm pretty antisocial, basically I don't have any REAL FRIENDS. I hang out with 2 girls and the group. One of them, one of my supposed "bff" is, I don't know, a fake friend. I mean, she uses me for (I don't know, but she doesn't like me that much) and I stay with her because I really don't want to be alone. But then, I have this girl, my supposed "BFF", my girlfriend, my I don't know, my best friend.. BUT I HATE HER! I always hated her and been very jealous of her, because she is very lucky with the guys, and everything. I mean I consider myself prettier than her but she still gets all the guys! And it's only because she has beautiful green eyes, but beside that, she is not that pretty. She is very mean and fake, she has a horrible hair and she is short! I know I explode of jealousy but it's because I don't understand what people see on her, and feel depressed because everyone loves her and I'm the loner,ect.. I am very tall, very, VERY, and VERY, VERY, VERY pale, straight blonde hair and brown eyes. Oh and I have braces �� But people don't give me chance. Right now she's pretty mad at me because I've been very indifferent to her. But I still don't care. The only thing that I want is how to overcome jealousy, because I'm about to explode. Oh, and I want to know too how to be alone in the recess because if she stills behaving like a b*tch I will .. I don't know, "break up" with her? Please help me, I can't take this anymore.