If you find a new Dr. maybe he/she can go over the medications you are on and make sure that is not what is causing some of your symptoms. It sounds like anxiety and fibro fog to me though. When I am anxious or upset I can't hold a thought. You started getting fearful of the tingling/numbness in your feet and fingers- and then nervous about doing the pieces.
Leerie, I get the numbness and tingling alot in my hands and feet. It is not a comfortable feeling but it is just a "symptom" and it will not hurt you. If your hands or feet get the numbness or tingling, rest them, even if it is just a short period. And if they are real bad and you want to go to that class you might not be able to that day. Especially if you feel you can't perform. I'm learning with fibro each day is different and take it one day at a time.
Hope your feeling better!