Re-visit your GP.
I had awful back troubles, had a MRI-scan which showed exactly what/where the problem was. I then had treatment specifically designed to help - physio, acupuncture, traction, cortisone injection. I was on pretty heavy meds, too (couldn't get on with Tramadol - it gave me auditory hallucinations).
All gave short-term relief but they helped with the symptoms rather than the root cause.
Eventually, I had surgery and the difference was amazing. I'm not 100% and never will be but I'm in a far, far better place than I was and get by ,in the main, on shop-bought painkillers.