This has bothered me from time to time for a long time too. It usually affects me most when I get to make other people do things I though they would not do for me. I've got no cure or definite answer for it.

On the other hand I felt the same of my dancing abilities (and still do) but being praised(+) a lot by lots of people, some of them being international dancing figures, and one of my teachers - whom I find an excellent dancer - asking me to enter into her (not truly professional but important to her) dance company has made wonders to improve my self-image. Even though I feel clumsy from time to time, once a dance or so ;)

So I guess trying to improve more in what you feel you do badly until everyone praises that aspect of you can help it.

(+) I've got to say the praises where not about my technical level, but more about energy, fun and all the things that make a dance alive.