Self confidence is often hard to come by, and that's exactly what you are lacking, self confidence.
After reading your post I think you know that you are a good looking guy, obviously others think so too, so what's the problem? What do you see when you look in the mirror?
We all have things that we'd like to change about ourselves, fat in the wrong places, hair color, height, eye color, whatever. It's not what you have, it's how you feel inside that counts.
You need to work on yourself, not the exterior, but the interior, because obviously something is causing you to feel inferior to others.
Don't be so hard on yourself, concentrate on the positive aspects. Also, it's not how you look but how you act that really matters in the long run.
Good luck.