I feel likeim not good enough for her?

I'm 15 and I'm going out with a girl who is really nice, talented (she plays both violin and base), athletic (long distance runner), and an all around great person. And I feel so plain I'm fairly out of shape ( working on fixing that though), a huge nerd, I can sorta play the guitar and I'm an ok artist and a decent writer. An a lot of kids think I'm crazy which may or may not be true I know I'm pretty weird but so is she she screams whenever toast comes out of the toaster but I think its kinda funny/cute but I'm really rather plain compared to her and well I'm a loser and she's not and I just don't feel good enough