Question about generalized anxiety disorder....?

I have had a feeling of throbbing in my back almost every day for over a year. I especially feel it if I am laying on my back or leaning back in a chair. Sometimes I feel it in my hands. The Dr. said it was most likely GAD. Even though I am not knowingly anxious, my body is in an anxious state. At times it is pretty strong and at other times I barely feel it. I was wondering if anyone may give me any ideas if this really is GAD or any information as to what might be the problem. I tried to take Paxil, but it made me feel nervous and lose my balance so I had to stop.