you seem like an intelligent and articulate person so my guess is that you are just one or two skills away from having good social skills
here's three things to consider;
1. start around your interests and hobbies - what interests and hobbies do you have? are you able to talk about these interests and hobbies relatively well? if so, look for ways to incorporate your interests into your social life to help you get practice and build confidence
2. build your skill set - borrow some conversation skills books from your library or buy some from your bookstore. listen to other great communications and learn the mechanics of of what makes them communicate effectively.
3. focus on your state - manage your state so that you give yourself the best chance of success in this area. breathe, be relaxed, control your focus and be in your best social state.
let me know your thoughts on these and all the best
edit: speaking of books, here's one I found on Amazon that seems like it could be very helpful for you
Amazon.com: Talk Like a Winner: 21 Simple Rules for Achieving Everyday Communication Success: Steve Nakamoto, Robin Quinn, Joe Kohl: Books