Just some ideas of the Auto Immune Diseases:
Immune Mediated Polyarthritis, Systemic Lupus Erythematosus and they should do more testing for Addisons. There is primary, secondary and atypical addisons disease. It is usually properly diagnosed with a ACTH stimulation test.
My thoughts and prayers are with you. I keep getting on the computer several times a day hoping you will have a proper diagnosis and treatment.