Suggest Medicine For Chronic Pain On The Back

Hi, I have had chronic pain (side, back and front on right side only) for several years. It started about a year after I had Lieomyosarcoma with a IVC and right kidney resection. The pains have gotten worse over the last two years. Three neurologists have prescribed, Gabbapentin, Gabbapentin, and Atavan to sleep. pain management prescribed Methadone on top of those. Accupuncture said stop Atavan and Methedone to see if Accup. works. I ve been seven times and no help. I also have had a growling and semi-diarehia for about six weeks. Sounds like the third world war in there. My internist said stop the Gabba. and the accup. and start Methadone. This is apparently a last resort. I have chronic-severe stage iv kidney failure in my remaining kidney. Will I kill that kidney by taking Methadone for life and bring on dialysis sooner? Any other suggestions for the pain? Could I have paralytic ileus and how is that discovered? Is Pot a viable thing? Sure hope you have some answers. I am a married male, 77 years old. Thank you. All of my doctors are at HUP here in Philadelphia.