I don't know what you eat, nor the meds you seem to take. Reports of side effects from meds have to include every reported symptom and are not necessarily reflective of most peoples' reaction to a med. But the sort of symptoms you describe could easily be explained by diet (too little protein, too many carbs) and dehydration. But I think Anne is spot on in her opinion, and it just seems to me that you have reasons for not really being invested in addressing the issues in ways that could be within your control. There will always be another med test you can pursue; but the more exotic the condition, the less likely it is that you would have it, given your normal test results.

Maybe it would be worth it to talk with your T about what you can do to change this attitude around and learn to gain security from taking care of yourself. I think this is what she's referring to by encouraging you to take control. FWIW, I do think the sort of somatic work you've been doing for so long can exaggerate a hyper vigilance about body symptoms.