Very self concious...

Hello. I'm a 16 yr old female. For some reason, I am super self concious about my butt. And I often find myself looking at other peoples butts. (Oh god I'm weird.) I feel like people are staring at mine, constantly, even if I'm home. I don't like wearing jeans or anything tight. Well actually, I'm self conscious about looking sexually attractive in the first place. (This is gonna sound really dumb.) I feel like some creepy older men are staring at me and are gonna do things to me. I know, very weird. And irrational as hell. I was not sexually abused in any way. Anyway, how do I get over this?