When you get those feelings of. "Damn...I should of done it that way, or, I should have said that" Those are the things you need to start changing and to work upon, don't beat yourself up about it. Take small approaches to improving your social life, I am not really a social person myself and I tend to stay away, I don't get a feeling of being lonely very easily. But when someone wants to talk to me, i'm always up for a lengthy conversation. Just makes the changes you feel you need to change, it's you that is in charge in the end anyways. Of your emotions that is.