Please help me with some bf issues?

I'm 15 years old and never had a boyfriend. I'm kind of overweight and not one of the popular girls. This is my first year in public school but no guys have noticed me like that. No guys liked me in my old private school either. I think I'm a nice person. I tell myself and my friends that I'm ugly but they tell me I'm pretty. If I was to be totally honest I don't think I'm disgustingly ugly but not gorgeous either. I'm a COMPLETE virgin, I've never been asked out, never held hands with a guy, never really hugged a guy outside my family. I have trouble talking to guys sometimes because I've never really had a relationship with one. All my friends talk about their make-out sessions and things during sleepovers and stuff and I can never say anything. No guy has ever called me pretty or asked me out or loved me. I feel left out and alone. And please don't tell me any bullsh*t like, "Oh, you're so young, just give it time," because I've heard that a billion times in the last 3 years and I've been waiting and waiting for my turn but it never comes. Is there something really wrong with me??? What can I do to make guys like me? I don't want to put myself out there and act really slutty 'cause that's not me. What should I do? Please help!