FWIW, some might want to try Qi Gong - a sort of toned down Tai Chi is the much simplified way I'd introduce it.
There's a Japanese therapy I just read about that translates into something like Gentle Heat if I remember correctly. Infrared sauna followed by warm blankets, again if I'm remembering correctly.
Promising research is focusing on very, very small (trace) electrical current applied to electrodes attached to the scalp.
Tens units to my knowledge were originally available, targeting muscle development & training. While originally claims were to increase muscle size through electrically stimulated contractions, the real benefit was as an aid in pumping out lactic acid after a workout, and then wasn't all that effective, or as effective as massage. They weren't that expensive at the time - something comparable to the unit pictured was less than $50 - though I haven't any idea if they're still available thru stores selling athletic supplies, supplements and such. I would assume the pricing increased partly from the medical emphasis, & partly if they get away with it.
I'd have to question if the benefits ascribed to Tens were from stimulating the muscles rather than nerves, allegedly interrupting pathways etc, & would strongly suggest getting an un-biased, qualified medical opinion from more than one source if possible.
For neurological pain, with the exception of disorders like FMS or sciatica, there's usually something effecting nerves, and removing that root cause is the preferred way to go AFAIK. Sometimes that takes surgery, other times exercise, massage, stretching etc. Sometimes you can even get away with nutritional supplements &/or diet - there's a lot of new writing out re: vit. D, how most of us are deficient, & how it can cause pain. The hard part is finding a doc or docs who will ferret out the cause, and insurance will not always pay for all the exploring. Holistic medicine can provide some innovative & often worthwhile treatments, but, as their focus is on making your whole body well, you might spend a lot of time and effort without effecting your main issue - pain.