Given the (amount of) testing you've already gone through, and your doctors' apparent willingness to help you zero in on the cause(s), I think you might (if it hasn't been mentioned) benefit from Liza Jane's Charts.

Also (if not previously known/mentioned), it IS common for many of us to experience flares and abatement of some symptoms, flares being brought on by triggers/trigger events -- abatements by... doing something right. This can be helpful in providing clues for both diagnosis and treatment.

Keeping a journal can help in discovering/finding catalysts (for bad and/or good).

Doc