I feel sorry for you because you're realizing so late that he's an asshole, but you also deserve it for not working up the nerve to talk to this guy earlier. It would have made life easier to find that out sooner.
I knew my friend for years, and I waited WAY too long to tell him how much I cared about him. 3 months into us dating he died in a car accident. My point is, don't wait for that shit, do it as fast as you can. Rejection is not as bad as we make it out to be.