You might consider looking into buprenorphine for your chronic pain. I too was on Percocet for about 17 years following back surgery. But due to the acetaminophen in the medication I was concerned about my liver. I first switched to long acting morphine sulfate pills following the Percocet but they didn’t tamp my pain sufficiently. I went to a rehabilitation/pain doc who prescribed buprenorphine patches. The drug in pill and film form is used in addiction medicine while the patch is used to treat chronic pain 24/7. Please read https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4675640/