I think confidence is lacking here...
For example, im not happy with my body atm, but im doing something about it so that when i go to the beach, greenpeace dont turn up and try and push me into the water..
If your having a hard time socialising, then you have to immerse yourself in a crowd, bit the bullet and just start talking...
Its daunting and scary, but, if you are in that situation, you have nothing else do do but socialise...
I was shy and couldnt talk to people well, but then i started working in a nightclub, i see thousands of people every weekend, and most want to chat, or fight, or grab your balls when you have no free hands... But now i find it real easy to talk to anyone...
Confidence is the key, get a bit, then a bit more, and it all compounds..