Why Do I Feel Insecure In School?

So I go to a school where I would say about 50% of the kids are black and 48% are white (I'm in 8th grade and go to a small Catholic school with only 178 students) anyways, most kids at my school aren't the greatest looking but in my class particularly, there's maybe a few good looking kids. Anyways, I'm friends with this girl she's light skin (half black, half white) and everyone seems to think she's gorgeous, there's 2 other girls who I'm friends with that are both black and everyone thinks their gorgeous. I just feel so insecure, I'm white and I don't think I'm ugly but the kids (mostly the boys) make me feel that way. I have 12 girls in my class, and us girls found a list the boys (there's only 6 boys; 5 black. 1 white) made naming the top prettiest girls. I was number 4 which is I know is good, but for some reason I didn't think it was good enough. It's other reasons too why I feel this way. My parents are always calling my brother beautiful, and never comment on my looks. One of my cousins said I looked pretty only in one or two pics. My other cousins always call me pretty when I feel down but you can tell they don't mean it. I just feel like no matter what I do, I'll never be pretty