I've had an Idiopathic, progressive, sensory, symmetrical, polyneuropathy for 11 years. My PCP and neurologist tried every off-label drug in the chronic pain pharmacopeia. Finally they sent me to a pain clinic. This is where you need to be, at least until you can manage the pain on your own rather than allowing it to manage you. Once you have the pain under control, your family doc may be willing to take on the regular prescription refills with occasional Pain Clinic referrals as needed. One thing you need to understand, and I still struggle with this myself, is a cause may never be found and you will probably always have some degree of pain, all day, and every day. That being the case, you and the docs are left with comfort measures. For example, Lidocaine ointment rubbed into aching feet can tamp things down to a tolerable level. Having failed the normal pain management drugs, the doc at the clinic prescribed low-dose Methadone as a long-term, maintenance narcotic at the lowest clinically proven therapeutic dose. This allows plenty of room to move over the next 30-40 years before I find myself shuffling off this mortal coil. I use a short-acting narcotic for the inevitable break-through pain. Even so, I still have days when I don't want to walk very much and life pretty much stinks. Doesn't mean there aren't some good days here and there. Hang in there--you can eventually arrive
at some degree of acceptance of an unchangeable situation once you manage the pain.