With a complex issue/s that aren't clearly defined by tests you might consider consulting with a DO ( Doctor of Osteopathic Medicine).
Difference Between MD and DO: Choosing the Right Doctor for You

The DO Difference - Doctors That DO | Doctors of Osteopathic Medicine.

Family health history - if any similar or know health conditions. I'm sure Drs asked about that..

Any past injuries that might be showing up as you age?
Accidents, sports, falls etc. or possible toxin/chemical exposures?