First, the surgery at L1-3 for schwannoma removal will not cause your symptoms in the shoulder. The neuropathy in your feet probably is caused by typical aging nerve degeneration over time (I assume you are in your 50s or 60s). See the section on peripheral neuropathy on this website).
If you have neck pain and unilateral shoulder/arm pain, you do not have fibromyalgia. Fibromyalgia is pain found in all four quadrants of the body.
Lower back pain is diagnosed by discograms if pain is generated by the disc and if generated by nerve compression, an epidural will give you some clue as to pain origin. You will not have any relief of your bilateral foot symptoms if these symptoms are truly generated by the peripheral neuropathy.
Did you have a diagnostic SNRB (selective nerve root block-see website) in your neck? This will help diagnose the origin of the arm pain. Did you have a shoulder specialist look at the right shoulder to rule out pathology here? Did you have an EMG/NCV (see website) to look for nerve disorders that would reveal themselves with these tests?
You need a well skilled diagnostician to look for the source of these symptoms.