Have Had Post Herpetic Neuralgia For Ten Years. Have Visited

Have had post herpetic neuralgia for ten years. Have visited many doctors like at Duke, Mass General and elsewhere. No solutions except Percocet for the persistent pain on upper left-side torso several inches below armpit. Have tried everything like gabapentin,lyrica, cymbalta, lidodern, etc. Any hope for me?
Incidentally I use opiate pills sparingly. I suffer and make life less than good for wife and family.. And at age 86,I have resisted Spinal electric stimulation as being a poor invasive choice, but I did go through the qualifying process successfully last year.