Sounds like you've had a fairly good start in regards to lab work up and getting proper supplementation and diet change going.

I'd still think you'd benefit from autonomic testing...at the least tilt table, holter, QSART, and gastric empty test (to confirm what sounds like gastroparesis). There are many medication options to help your symptoms once your conditions are confirmed. You'd have to stop the Domperidone before doing the gastric empty test.

There are many, many people with idiopathic PN...with accompanied autonomic neuropathy. but that doesn't mean you can't treat your symptoms and improve your quality of life. There are BP medications to help with orthostatic hypotension...like Midodrine or Florinef. Some get help with just a high sodium diet to help retain fluids to keep BP up. I use all the above. But again, you need to be tested before starting any treatments like this. Gastric motility problems can be improved with Domperidone, but some basic diet changes can also be helpful. Eating small meals and avoiding nuts, raw fruits and veggies (steamed/cooked veggies are fine) can make it easier to digest when motility issues hinder breaking down food. Also walk after eating (gravity really does help) and avoid eating in the evening to avert night time symptoms. I use a wedge pillow, as the slight elevation again uses gravity to help keep the stomach empty and reduce reflux. I good probiotic is a must as many with gastroparesis develop small intestine bacterial overgrowth (SIBO). This will increase all symptoms. The kefir as MrsD suggested is perfect.

When I first became ill and disabled (1996), I lived in the Dallas area (until moving back to VA in 2006), so I am familiar with UTSW and a few other facilities in Dallas. UTSW does have a sizable neurology dept, but some of my autonomic testing (tilt table and gastric empty study) was done even at Medical City.

You don't mention Lupus testing or basic ANA lab? Was this done?