Can anyone help with systemic symptoms that have doctors stumped?

[Lelulily]

About 5 years ago I had odd proximal muscle pain in thighs and upper arms. Pain included a lot of burning sensations. Had difficulty with lifting my arm to do my hair but no other weakness. Thyroglobulin was at 1900 and had some thyroid level changes that leveled out after a few months and was diagnosed with thyroiditis but never treated. Symptoms stopped until this October. I had a horrible upper respiratory illness that stopped me from working out. I have lost 60 pounds since April. Since the virus (which resolved) I developed the same symptoms as before, but much more severe. Legs feel funny and get easily fatigued, severe sunburn feeling that radiates to my chest and causes increased hr and bp, respiration slowing, chills, can't regulate my temperature, severe dizziness, and fainting spells, and heart fluttering. Thyroglobulin is in the 1000 range, intrinsic factor is elevated (but normal b12), and thyroid levels are normal. Pyruvate is low. Emg shows nonirritable myopathy. All other blood levels are normal. No one knows what is going on. Have a rare autoimmune disease but other than that no issues. Any ideas?!