Strange that the OP put this up here. We were talking about this at an AA meeting tonight. I can tell you what I did if it is any help.

I purposefully isolated myself for a bit, just to get to figure out what I liked to do that didn't involve drinking. It didn't take long. I started building models, searching out hard to find movies, finishing my xbox games, stuff like that. I learned a lot about who I am and what makes me happy. From there, I went and found other people that liked to do the same things. It isn't always easy, but it happens. Also, you may come to realize that you are just shy and introverted and there isn't anything wrong with that! I am that way and have come to grips with it. I am, nor was I ever, the life of the party. But, I am a good listener and I ask good questions and that can go a long way. It gets better, believe me.

As for getting out? I, again, do what makes me happy, whether it is alone or with a freind. I go out to the movies alone, i browse the bookstore alone, i have even gone to eat alone. If you go to the same places that you enjoy alone enough, before you know it, you will see some of the same people, often alone themselves. Then guess what happens? You aren't alone anymore! Just do it and it will work. And keep going to the AA meetings if you are doing that. If not, start. It may be selfish, but it gets you out and gets you interacting with people.

Hope that helps.