Anyone experience chronic sit pain from hamstring/sciatic adhesion?

I began experiencing chronic sit pain in my left sit bone area out of the blue 5 years ago. It was present as soon as I sat down and went away as soon as I stood. I only had pain when sitting but it became severe the longer I sat. Dr suggested piriformis syndrome. Had months of PT. Exercises made it hurt worse. Was sent to an orthopedic surgeon. My L4 &5 were herniated but not significantly. Had an injection. No help. Over the course of the next 2 years I had 3 MRIs, Ishial bursa injections and 3 other injections. None helped. Finally had surgery on the disks. No help. While working in my yard I tore my left hamstring. I had injured it 7 years before. This tear was severe and required surgery. The surgeon was aware of my sit pain and explored the area. He found a 2cm "nubbin" that I assume was scar tissue probably from the previous injury. He removed it. He also noted that my sciatic nerve was adhered in several places and he freed it. Post surgery I experienced some relief in my pain. It did not go away but was much better. Where before I could not travel in a car more than 2 hours, I did as many as 12-15 on a vacation. That lasted about 16 months and now the pain is back like before. Only now it hurts if I walk too much and lingers when I stand. Sometimes I can even touch the area and get pain. I cannot do any sort of exercises below the waist or nerve glides without irritating it worse. I have been in PT the entire time with no relief. My PT thinks the nerve is adhered again. I am otherwise a very healthy 65 year old who works out regularly (upper body only) and am as active as this pain will allow. I am not sure where to go next but I simply refuse to give up...I'm stubborn! If anyone has had a similar experience or has any suggestions I am open to your thoughts.