Difficulty socializing since breakup?

So I used to be pretty funny. It was one of the main reasons I was able to get my girlfriend in the first place. We both went to the same college and we broke up and now I cant talk to ANYONE! I have incredible difficulty even starting a conversation with a friend. I was very sociable during the first half of the relationship but nearing the end I was having some difficulty but now this is bad. I have friends, but they all live in my hometown or are at a different university. My roommates and I sometimes hang out but I feel that it is too late to make some friends especially when I constantly have my foot in my mouth.

Is there something to do, or do I have to start over?