How do I fix the problems with myself that have come about since me and my ex broke up?

My boyfriend and I have been apart since April of last ear. We were going through a rough patch and I decided to give him the space he needed so we could work it out. Needless to say we didn't. But he was my first everything and it hurt but slowly I moved on to the point that I could start dating again wothout feeling too guilty. But as it turned out everytime I would date them and it got to the point where we could do everything but have sex, and I would start feeling sick if they did anything sexual to me. And after a fling ended, as ong or brief it was I wouldn't feel bad I'd just resort back to thinking about my ex and how much better things were, even when they were shitty. Its gotten to the point where the idea of having an sexual contact doesn't interest me at all. I hardly ever hang out with people either if it means me having to make effort to get to them. My personality is even effected. I guess I could be considered odd and quirky, but I don't care. Just give me your opinions or suggestions. Good or bad, whatever you got.