Bif, I can relate to what you've said about not feeling special in any way. I've felt that way about myself for many years during my teens.
I remember that when people told me things like "everybody feels that way sometimes" or "it's normal to feel that way", I thought they were not helping me at all. So it's weird for me to find myself compelled to tell you such things. But you know what? They might be true.
What I can tell you for sure, is that it took me a lot of time and effort (and some therapy here and there) to learn to appreciate what I can do and who I am. It's funny because the things you are good at sometimes are there, but you just don't give yourself the credit. Don't underestimate the things you do, it might lead you to neglect them and then regret it in the future; it happened to me. Trust me,
is a bitch in that sense... it just goes so fast.
And the girl. Well, I don't feel in a position to give you advice or anything, but I'm going to say 3 things: 1) There is always room in life for a comeback (sometimes more than one), specially when you are so young and when you two parted in good terms. 2) The first love is special. Even if you don't see her ever again, when the wound heals you'll have a pristine and beautiful memory of the time you spent with her. 3) Have patience, and be excited about the future. After the fist love, comes greater, stranger, and more vivid love. So heads up bro!!
Big hug