Feeling guilty...Advice appreciated.

I really liked a guy for over a year, and now he finally likes me back. He told two of my really close friends his friends are pressuring him to ask me out. A few months ago, this would have been the stuff of fantasy, but as I’ve matured and met new people, my feelings for him have disappeared. I’m extremely non-confrontational, so instead of being direct with him or his friends, I’ve been flat-out avoiding and ignoring him. Besides making me feel awful and immature, this strategy hasn't been working. He noticed my weird behavior, since he’s a smart guy, and even commented on it to the earlier mentioned close friends. This guy is also incredibly sweet and deserves much more respect than I’m currently giving him. Because we’re going to be stuck together for the next four years, I also want mention, if nota friendship, at least friendly relations. How do I deal with this situation in a kind, respectful, mature way? My week has been made much worse by the constant stress of our current dynamic... I just want to be done with it, but know this is not a rip-off-the-band-aid situation. Any advice would be appreciated.