Hop on over here and read for a while... it's the asexuals message board: http://www.asexuality.org/discussion/index.php

Also go read about this book on Amazon... just the blurbs there and the excerpts are very interesting:
Sexual Anorexia: Overcoming Sexual Self-Hatred

The premise of this book is that "sexual anorexics" deprive themselves of sexual pleasure the way food anorexics deprive themselves of food... and for some of the same reasons. Both groups literally starve themselves in the midst of plenty. I got the book thinking it might apply to my bf.