Had Spinal Thoracic Fusion. Why Do I Have Pain And Numbness In Limbs Now?

A little over two years ago, I had a seven level thoracic spinal fusion . Shortly thereafter, I began to have pain and numbness in my legs and hands. Toes, top, bottom, calves, thighs, buttocks , fingers, forearms, you name it. I have been seeing a pain managment doctor who has been treating me with epidural shots, which have not been working, especially recently. I have been imaged from brain to lumbar and they say everything is fine now. So why the pain. I have recently been having some palpitation that I had not mentioned.. Once bad enough to go to the ER with a heart rate of 172 according to a home machine. I was sent to a neurologist who also did some blood work that showed an elevated ESR but no findings of MS, Lupus,. etc. Now the neurologist is sending me to a cardiologist . I have a brother who almost died of heart failure two years ago at age 50 and a dad who had PAD and died of aspiration pneumonia last year. I have had diabetes for 14 years, extremely well controlled. A1C ranges have always been 5.5 to 6.4. Can you explain my leg pain. It is much worse in the evening. I usually sit in a reclining sofa. They will occasionally hurt (numbness) when I do my PT exercises.