Are you able to spend time socially with just one other person? Perhaps a relative if not a friend. I would try to build up your confidence gradually with smaller groups of people. Alternatively could you try a new hobby or activity where there are new people with similar interests to yourself? Then you might potentially worry less about talking because if you don't like it you won't have to go back and see them again.
Could you try to explain a bit more about what kinds of social situations you are afraid of and if you know why it makes you anxious?