My Dear Mimi56 I am deeply sorry that you are having such a difficult time. I too suffer from an autoimmune disorder and after seeing 3 neurologists do not know what I have. From doing a bit of research on my own and benefiting from the commentary on this site, I've learned that these disorders are very difficult to diagnose and treat. Certainly some present clear as water and fortunately respond to treatment. Then there are those that fall between the cracks and depending on the neurologists you see a particular condition is pinned to it, however treatment is something else. Since no specific conditon can be clinically established, you'll get something for the pain and other symptoms but nothing to treat the cause itself because no matter what you may have been told, the neurologist doesn't know what you have;and she/he is not going to take a risk on treating a conditions for which there is no real, solid, clinical evidence. Of course, somewhere down the line they'll finally tell you this.
Nevertheless, you must do everything to help yourself and looking carefully at your diet is essential. Feeling anxious and helpless can lead us to eat more of the wrong foods. Since you're unable to exercise cut back on the calories; go for the vegies, (yes, I know easier said than done). By all means get a second opinion and a third if possible. In short, keep on struggling, asking questions, gathering all the information you can on your symptoms, but do not act on anything that anyone tells you without first talking to your primary doctor, who you very evidently trust.
You're in a fight my friend that may prove to be long and hard, but you've come to the right place. Here people care and will, i'm sure, provide you with lots or really helpful information. Hang in there Mimi and trust that my heart goes out to you because I'm in the same boat. All the best, Awlright