Hi Doc, I Am Experiencing Severe Legs Pain, Causing Me

Hi Doc, I am experiencing severe legs pain, causing me unable to walk or stand, using a walker to help. Although I have a herniated desk at my back, but I was told that I am not a good candidate for surgery because of my age (81) . Some doctors recommended to do a Lumbar-Sacral Rhizotomy and burned the nerves, but did not help the issue at all. The pain won't let me sleep neither if I felt to sleep, the pain awakes me up. The doctors gave me Tylenol three with coding to help a little, but the insurance now has instructions and regulations not to dispense it. Caused me to take Extra Strength Tylenol 2 pills up to two times daily but pain still there. No doctors were able to help.
I am seeking for a doctor that can figure what's exactly causing this severe pain and how can he help even if the medication that he gives help the pain a little pit so I can sleep. Thank you in advance