I suffer with Fibromyalgia and back pain. Is there a drug under Morphine to treat this better than percocet?

I am on the Fentanyl Patch at 100mcg but it doesn't help Fibromyalgia along with chronic back pain. They gave me Percocet 7.5 for intermitten pain but it doesn't help. Have any suggestions. I want to know if there is a drug that is strong enough under Methodone that will help control the pain. I am tierd of living this way.