Hi @lewin, I know it's the pits not to know the exact cause of your neuropathy and living in constant pain looking for something that helps. You mentioned bad arthritis in cervical spine. Nerve compression in the spine is something that can cause neuropathy symptoms. Here is some information from Neuropathy Commons.

"Trauma Or Compression
A common cause of nerve injury is physical trauma to the nerves, such as by injuries, falls, sports activities or surgery. Nerve function can also be compromised by other body parts pressing on the nerve. An example is sciatica, which is caused by a degenerated disc which allows a vertebra to press on a nerve root, causing pain in one or both legs. Another example is carpal tunnel syndrome, in which wrist structures press on nerves. This often comes from repeated activities like typing or hammering. Tumors, scars or bone spurs can also press on nerves and cause damage. Tight casts can inflict external compression that impacts nerve function."
--- Causes of Neuropathy: https://neuropathycommons.org/neuropathy/causes-neuropathy.

There is a discussion on Myofascial Release Therapy (MFR) that might provide some relief from the symptoms -- https://connect.mayoclinic.org/discussion/myofascial-release-therapy-mfr-for-treating-compression-and-pain/.

Have you thought about seeking help at a teaching hospital or major health facility?