Why don't women like me?

Ok, so i am a slim but a lil muscular 20 years old. i think i look about that age, some people say i might look younger, some older. I'm only 5'8" so that's probably why i look younger. I got long hair and i'm not the ugliest guy out there, but not the best looking. anyways it's like if women over 18 don't even look at me. If I try talking to them, you could tell they think I'm some weirdo. Like if I'm not on their level.Even chubby chicks (which i f'ing love!!! but they ignore me like I'm trash) I always notice little girls staring at me giggling with their friends, or coming up to me telling me their friend thinks I'm cute. AND ITS FREAKIN WEIRD!!! i mean i don't even know how to respond to things like that. today i was at an amusement park and through out the whole time i was waiting for a ride, A GROUP OF LITTLE KIDS JUST STARED AT ME!!! like dead on, i look down, they're looking up!!!! and what really got to me was while i was at a store with a friend, some mom with her kids n i guess adult daughter was there. I thought the mom was hot and the adult daughter too, but they didn't even glimpse at me. As i walked passed her little 9 - 12 year old daughters, my friend noticed they were starting at me and he told me, " Hey them little kids are checking you out, they probably think you're a jonas brother reject"(since my hair is like Joe Jonas). and it really GETS ME FRUSTRATED!!! anybody else have this problem?