Op, I hesitate to even suggest this, but have you considered removing grains (all of them!), but especially gluten containing ones from your diet for a couple of months to see what happens?
Obviously this is not going to work for everyone, but many people get at least partial recovery from autoimmune conditions on a grain free diet (so require fewer drugs), and many others get a full resolution of symptoms as long as they stay grain/gluten free.
I am always very aware when Have eaten something I shouldn't (usually but not always, by accident). I get fairly rapid joint flares and typically very dry eyes/ mouth for several days (I can wake in awful pain with eyelid seemingly ripping off my eyeball as they stick together).
I am in my 40's and seem to have followed the "typical" trajectory of many years of increasing, probably autoimmune related health issues, followed by developing much worse (diagnosed) issues as I reached my 40's.... But now, I am healthy and not in pain (I had constant joint, bone and muscle pain, migraine, digestive problems, blah, blah, etc).
The funny thing is, I actually cut grains from my diet for other reasons, and was blown away by the sudden resolution of my illnesses, provided I stay grain free I am absolutely fine.
I will repeat again, obviously this won't work for everyone, but there is a lot of research about grains (especially gluten containing ones), and the development of autoimmune conditions (diabetes, thyroid, arthritis... A very long list of other things). The only way to find out is to exclude grains for a couple of months and then reintroduce them one at a time, and see what happens!
If you have no grain sensitivity/allergy /intolerance, then it won't make any difference to your symptoms but if you do, you can expect to see symptoms reducing within days. You may also get a worse reaction when you try to reintroduce grains (for me, significant stomach pains within 15-20mins of a mouthful of gluten containing food).
Exclusion diet will only work if you properly exclude grains - and it's not easy unless you cook everything yourself. I discovered my grain intolerances (I had long suspected tho!), doing the Paleo 30 day challenge (it's palaeolithic food so no grains at all!). If you are interested in looking into this further, you might want to have a look at Robb wolf 's paleo diet blog, and marks daily apple (primal blueprint), blog, or dietdoctor blog (Swedish lchf diet). All the info is free, although there are books if you want to buy them.
Apologies If you have already tried dietary therapies with no success 