It was 'pancreas' in the title that made me look, and I can't add anything to the astro-discussion but two medical things:
You say the diabetic diet doesn't help you, makes me wonder *which* diabetic diet (controversial! lol) but
Remember there is Type 1 diabetes as well as Type 2. Type 2 is the kind everyone knows someone with. Basically in type 2, the body's insulin isn't being used properly or fully, but in type 1 - something like 10% of cases - the body isn't making any - same outcome obviously. (Type 1 is why I've been on insulin since I was six so I have read a lot of issues of the Diabetes UK magazine!)
What I'm waffling around to is, you need your blood glucose level checked, to be sure about either type.
And I have fibromyalgia too! You only mention NSAIDs and pain relief - but they are not the meds of choice for fm. Amitriptyline is the first they ought to try, then I switched to duloxetine and there's another, I forget the name. Each works better on different symptoms (the pain, brain fog, IBS, fatigue, sleep disorder, etc) and some people do badly on one but well on another. I'm sorry I can't find the article I was thinking of but try fmauk.org to begin with. (Low-dose anti-depressants do entirely different stuff from the dose they use for depression.) FM is not an arthritis, it is a neurological condition, or even a family of conditions, the research would be fascinating ... if I had the oomph to keep up with it!!
And medication isn't the treatment of choice anyway, a pain management course would benefit you if you haven't been on one, and pacing is SO important - the concept is simple but it took being really taught it, for me, and I still struggle. (Two years after my pain/fm course, three years after diagnosis, though maybe ten years after developing fm... or twenty, who knows, it's so insidious...)
Apologies if some or all of this is old news for you, but it didn't sound like you have heard it, from quickly reading through (and I may have missed a bit). Which would be like most people, for years after getting the condition. Anyway it could help someone else reading it, attracted as I was by having something in common with this thread.
Hang on in there, don't give up yet on things improving.
mm