Thanks for the links, will do:
There are many triggers for PN... common drugs, toxins, and even that vaccine you got because it was advertised on TV or elsewhere.
I've tested for drugs, toxins, and don't get vaccines-negative

You need to check nutrient levels for B12 and Vit D and get the numerical result instead of "normal" comments from your doctor. Doctors will test but they don't often interpret the results accurately.

My B12 is 700(mid-range) and D is 60 (optimal range).

Also magnesium may help.
I've tried that, the best absorbable type, and it didn't help

What your doctor can do for you testing wise is limited, as well as treatments.
I don't understand your comment about DRS: A doctor should test a patient for all aspects of neuropathy, because if it is an autoimmune triggered neuropathy, IVIG and other treatments are available for those patients.
Thanks!