In certain ways, I have a fear of particular social situations that I better pull my blanket up and stay there. However, I said it to myself that it is not good at all to my self (regardless it is introverted or not). These are what I do to overcome my fear of social situations.
Force myself to go out at least once or twice a week. I did it. I go to campus and that's enough. It is just to help me to cope with my anxiety, ask a friend to do something with you, or go to an event where I know few people but not too crowded. The idea is to gradually stretch myself so that, eventually, I will be able to go to new things, and not feel terrified of meeting people I have never met before.
Pay attention to my appearance. When we feel good or at least comfortable with the way we look, we feel less anxious and more confident.
Find out what other people talking about such as popular movies, TV series, TV shows, sports, etc and read up on them. For example, you could google for the latest scores, headlines news and gossip on the stars.
When I am at social events watch to see how other people behave. I can learn a lot from closely observing, listening to, and then copying others.
So far, these all I can possibly do to cope with my fear of social situations. If you feel you can't cope with it, find a counselor to address the underlying fears that are behind your social anxiety. It is not a sin. It is good for your personal development :)