What you're describing sounds very much like peripheral neuropathy. It can be caused by many things: diabetes, exposure to some drugs--I have it in both hands and feet, and my Doctor's best guess is one of the chemo drugs I was given many years ago for cancer, but, on balance, I'm still here, so I'm not complaining!--and then, there's "idiopathic" neuropathy, which is just doctor-ese for "we don't know what caused it." As for treatments, there too, there isn't a lot of help. I've read that a supplement called "alpha-lipoic acid" is helpful, but it's so expensive, I couldn't afford it.
If I had your symptoms and had exhausted the possible remedies from my medical doctor without success, I'd try to find a highly recommended chiropractor in your area for more options. I have had the best results from UC chiropractors, like the ones listed on nucca.org.