Did you have any injections of any description before your PMR began? Flu vaccine maybe or any imaging dyes before a scan? Autoimmune Syndrome Induced by Adjuvants (ASIA) is worth researching if that’s the case.
As for our limited diet, roasting a colourful array of veg (sweet potato, carrot, onion, red pepper, beetroot, courgette etc) tossed in olive oil, varying the herbs/spices & maybe adding some olives or wedges of lemon is my go to food. Adding a piece of salmon, cod or chicken on top makes a lovely healthy meal - & creates very little washing up as it’s all done in one roasting tin.
I’ve resigned myself to the fact that I have to live with PMR now - but refuse to be governed by it. Taking control of diet gives me some control & researching to find answers helps too. As for blame? I’m angry with food manufacturers for contaminating so much of what we buy. The industry is being called out now & exposed for the harm it’s doing to us. It’s us, the consumers that need to refuse to buy the rubbish they produce - see it as the poison that it is. We need to take back control.