Have you been tested for thyroid dysfunction? Fibromyalgia is a set of symptoms, for which there is no explanation, but they correlate with symptoms of hypothyroidism. You might ask to get some simple tests performed to make sure thyroid issues aren't causing some of your problem.
Have you looked into yoga for exercise? There is a type of yoga for nearly everyone, even those wheelchair bound.
The key, however, is to limit calories to less than you use, daily. You have to forego sugary, starchy, fatty foods and opt for lean protein, low/no fat dairy, whole grains, etc. Portion control is most important.
I would love to comment but I have tried 2x and this frigging system just kicks me out every time Sorry - if I figure out the problem, I will answer your question