@jfd1969 The pain you are describing sounds a lot like thoracic outlet syndrome, and basically that is caused by tightness of muscles and scar tissue that compresses nerves that go into the arms between the neck and shoulder. Your surgical scar tissue will also have gotten tight and can be pulling into all of this. My treatment of choice which helps a lot is Myofascial Release done by my physical therapist. It is similar to massage except that the therapist holds the stretch with their hands and waits for the tissue to release. Here is a discussion where you can learn about all of this. The first pages have many links to resources.

Neuropathy - "Myofascial Release Therapy (MFR) for treating compression and pain"
https://connect.mayoclinic.org/discussion/myofascial-release-therapy-mfr-for-treating-compression-and-pain/
The best part of this is is works and there are no drugs involved, and it will get the body moving better and help get back into good body alignment. Any waste products held in the tight dehydrated muscle will get released when it can move correctly again and body fluids can circulate. It may take a series of sessions and patience to work through all the layers of restricted tissue, but it is worth doing. You don't need a diagnosis of thoracic outlet syndrome to do MFR, just your pain and restricted movement is enough.

There is an MFR provider search at https://www.mfrtherapists.com/.