What came first? That would help. And what meds are you on? Many do slow metabolism, such as ssris, for example, and most strong painkillers. The only unifying factor here is the fibromyalgia, which is a little understood disease that can cause all the other symptoms you're having, which is why I asked which came first. As for diet, the easy part to advise is to avoid anything stimulating, including caffeine and sugar.