Firstly, I think you need to see your doctor. If the Zoloft doesnt seem to be working, there may be other drugs used to treat social anxiety disorder and depression together. Also, it would be worth mentioning that the therapy isnt working either. Have you told the therapist that it started when you met your boyfriend? Possibly if the Zoloft isnt working for you, the social anxiety is starting to grow and you only want to spend time with your boyfriend because you feel safe and secure with him.
I assure you that you can do all those things that you mentioned, its just that you feel you cant do them at the moment for some reason. Perhaps it is a low self-esteem or a lack of self confidence. But you can do it.