I have something similar that started about 15 years ago. I get really stiff and "stove up" after being stationary for a short period. Worse after physical work - ie after working all day at the farm then driving 1.5 hours home, I can barely get out of the truck. It takes several minutes of shuffling like an old man before things "work right" again. I am positive for HLA-B27 antigen which makes me more prone to a autoimmune disease, but doctors just seem to shrug their shoulders and tell me to take Advil. I questioned the tick connection but it was ignored as lyme is very uncommon in MO even now, let alone 15 years ago. What other tests have you done, Jack?
back to topic - finally got around to buying the permithrin concentrate to make my own clothing spray.