Getting out of your shell.. how?

This is really a general question for anyone who has ever become totally isolated because of his fear of the world and managed to break out, even a bit.
(just to clarify - in Isolated I mean: not going out to parties, not seeing people you don't know (only friends), not dating and generally being ashamed of yourself and building walls around you)
And the question is - how did you get out of it? Are there any small steps to start with?

------- Don't have to read below to answer -------
The thing that happened a few days ago and made me think about it - I went to a center where people play board games/card games etc' and everyone was much younger than me (I'm 32) in 10+ years and I just couldn't bring myself to enjoy their company. I was totally afraid they'll ask my age or basically anything about me so I just kept talking about the games and made it superficial as possible. When they were closing up one of the employees tried to set up a game for next week. I told him I'll come but I'm not sure I can. It can't be superficial for ever, eventually I would have to say *something* personal. This is making me anxious. How ###$ up is that uh? I wish I could feel comfortable around people but this getting worse as I avoid everything.
Sorry if I'm not making sense.. :/

play the game wear the mask go for your goals
scratch that
one step at a time
your own pace
i dated a woman (37) with the same problem i defendly have a talent for psychology but i cannot do it over the comp (i'm probabley here to understand here)
if you want real help best to get a professional involved

Would it make it any more comfortable for you if you were to bring a friend and let them know what it is that you are trying to accomplish.

Maybe they could bring you out of your shell a little. Ask questions in a group setting that you would be comfortable answering. You could have already discussed things before going to wherever.

Or even try role playing with friends. Or start somewhere small. Maybe a coffee shop. Sit back and watch other people interact. That may help as well.

I've been in that situation. It's taken me over 20 years to get over my intense fear and anxiety about entering new group situations like that. I bet if you went a 2nd, a 3rd, and a 4th time, etc. that you would find the stress, anxiety, and fear lift by very very small increments each time that you went. I'm never totally 100% comfortable in group situations, but I find that I am not necessarily going to be paralyzed either with fear like I was 20 years ago.

What you said made complete sense to me and I struggle with the same anxiety. I seem to have this unshakeable fear that if anyone knew me beyond my superficial mask then they'd realise that I'm more trouble than I'm worth. The only thing I can suggest is to keep trying. Maybe it will get easier as time goes on.