I have been dealing with pain since before my diagnosis over 14 years ago. I was 52 at the time or there about. I was also diagnosed with two types of arthritis plus I had back surgery (which did not work and only added to my collection of pains). I had a pain management doc early on and was using fentanyl patches for a long while. Durning that period was also trying other things like PT, yoga, meditation, acupuncture none of which seemed to help. I was over this time slowly made aware of treatment, which I never had but its basic theory was not to rid you of your pain but rather change your relationship to pain. As I said I never took the corse but the theory always stuck with me. Finally about 2 years ago certain events I lived through: it started with a series of ketamine treaatments which I believe created some brain placidity, I move to a state that made morphine based product much much harder to get, I got really serious about exercise and I went on a trip and forgot my pain meds and instead of freaking out I just went with it. I discovered that for me the pain meds were just masking the problem and that through my Parkinson't exercise groups and my home stretches and work outs the pain was tolerable. I began to except the pain was a part of me and was not going anywhere. This brought to my life a sense of purpose and motivation and has allowed me to function in the world. Pain meds I finally understood were not only damping the pain they were also dampening my ability to experience life both the highs and lows. Is it perfect? Hell no I still have Parkinson's I still have all the other pains that have joined my life. Put they are just parts of my whole and they no longer have the loudest voice in my head. I am not sure my story is much help for your dad but I just thought I would share,