I Have R.A And Psoriatic Arthritis. I Take Methotrexate And

I have R.A and Psoriatic Arthritis. I take methotrexate and Remicade for them and Percocet. I have 7 herniated discs and recently the pain is intolerable. I told my rheumatologist and he said I need to tell my pain management dr I need something for pain other then what I am on. My pm suggested Morphine but I don't even like taking what I have. Is there an herbal or something different I can take? I can't have nsaids because I have had rny gastric bypass.