Sounds like your self-esteem is pretty low. This is normal for your age, but there are some ways to increase your self-esteem and make you more desirable.
You need to put on some pounds, man. If you look like a zipper when you stand sideways and stick out your tongue, start filling your belly, pump iron (as much as you're gonna hate doing it) and you'll notice a change almost immediately.
You'll start walking more erect because you're building up the muscles in your back. You'll feel more confident and that will enable you to get the courage to talk to women.
