Hey dude... thinking about it more (I missed my appt. because I wrote such a long reply! All good).

I think your symptoms fit Lupus best.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4918207/
https://www.ncbi.nlm.nih.gov/pubmed/7842532
https://www.ncbi.nlm.nih.gov/pubmed/27504292
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4826706/
Should see a rheumatologist, and start on immunosuppressants to bring inflammation down. They will probably suggest low dose Prednisone (steroids) or Imuran. Rituxan may be a choice, and can be an AMAZING drug.

I think Amitriptyline or Nortriptyline are worth a try, and risk/benefit ratio much better than immunosuppressants.
GI issues would try PPIs. Lyrica is good if you are having SFN pain.

Don't start too many meds at once, you want to stagger them so you can monitor what is working. Remember, it's all about patience. Truly.

I'd maybe see an immunologist for a run through, if the rheumy is not up to running all the tests. I can give you list of tests to ask to run. Remember, the doctor works for you. No reason they shouldn't run tests requested unless they are not familiar with tests and cannot adequately interpret.

Do you have a rheumatologist? If not where do you live? I can try to find someone if needed.

Hit me up!

Feel well,
Nathaniel