Fibromyalgia is an autoimmune disorder, and autoimmune disorders can do horrendous things to the brain, as well as to parts of the 'physical' body it decides to attack. Worse, when we have one we are targets for others.

I *trust* your doctors are looking at this holistically, starting with testing for low levels (there doesn't need to be a deficiency) of every vitamin and mineral financially possible. Inflammation (which is what autoimmune disorders produce) may be impacting your body's ability to pull vitamins & minerals from your food. If so, by trial & error discover the trigger - mine was an intolerance (not an allergy) to gluten/carbs. I cut them by half and increased my protein intake as my vitamin B12 was slipping, supplementing with a range of vitamins & minerals, from zinc to Vit-D3. The internet is our friend here: research your symptoms through this lens and see if it throws up any suggestions. People have trod this path before you.

You may know all this, be doing it by now, but it doesn't hurt to emphasise it, especially for other readers. I wish you well.