Something else I just thought of, and it might not make a difference to you but there's a chance you'll find it helpful:
One way of building social/ self confidence is through physical contact. I'm not suggesting you go round hugging everyone but certain sports and activities can do wonders for your interaction with others.
Contact sports like judo/ karate/ rugby would be good but they aren't suitable for everyone so if you don't fancy that, consider a first aid course or dancing lessons. In these situations you have to be close to people in a neutral, instructive setting which really builds your confidence. There is no embarrassment involved because everyone understands that the contact is simply required.
Just another idea
