Screwed up

[M]

I have a guy with whom I have been friends since the beginning of the school year. He and I started to become better and better friends, and he began introducing me to all of his friends. One of his friends seemed to like me, but then after talking to both of them, I got the impression that I was wrong about that. Anyway, I began to like my friend after that, so I started talking to him a lot more (even though I saw him a lot less b/c of our schedules) on the phone and such, and just becoming more involved in his life, and he seemed to respond similarly, so all of the signals I got were positive. Finally I asked him to dinner, but as friends--as far as I knew, he may have thought I was interested in him otherwise (which was also starting to fade away on my behalf anyway), but I couldn't tell. He said he'd get back to me, but then never did and started literally avoiding me on campus (I'm a freshman in college) and not talking to me. His friend that I knew still spoke to me and almost acted like nothing was different. His other friends that I knew very little of definitely acted strangely around me, though. I finally sent an email letter to him, about how important our friendship had been to me (I was having a lot of trouble adjusting to college life in all aspects), how I hadn't meant anything but just as friends when I asked him out, and how I wanted to start anew with him and that I would listen to what he has to say. So far, he hasn't gotten back to me, although he isn't avoiding me anymore and now says hello. I know he sounds like a jerk, but he is really shy and his floor in his dorm is REALLY tight and although I know one of them has a girlfriend here and they talk to girls, they really only hang out or seem to trust one another. So, it sounds like they've all found their comfort zone in one another. I think I have done all that I can to try to fix things on my end, but I am still somewhat perplexed as to what happened, because there could be a few explanations. If anyone has any suggestions or comments, I could use them! Thank you!