This has been hinted at in previous threads: If you can, get a job as a sales person at a retail store; even just for the summer.
I know it sounds like a nightmare made in hell , but trust me, this helped me TREMENDOUSLY, and others have also talked about how this has helped them. I used to be the absolute worst SAD sufferer
It will be tough at first but as long as you stay true to yourself, you would be amazed at the progress you will make. The surprising thing I learned is that even the most outgoing/extroverted people are awkward/get nervous/ say the inappropriate thing. You will also find that it's very easy to win people's confidence; just a smile, and a well placed word, and they will be in the palm of your hands. Working in retail just sets up the ideal situations for you to deal with people because you both will have something to talk about.
Once you start to gain confidence, your whole outlook on life will change, and customers will tell you the strangest stories about their personal lives even if you just met them because they have so much confidence in you.
P.S. I should add that I never took any medication though my case was really really bad. I'm of the belief that medication only treats the symptoms and not the issue itself. But perhaps your situation is different.