Can't get off long enough to see if I'm addicted?

I have an autoimmune disease called Dermatomyositis. It cause severe muscle, soft tissue and connective tissue inflammation and severe muscle weakness. In my case it is very painful.

I'm still undergoing treatment but and almost in remission. I'm on heavy duty meds, Fentanyl and Lortab.

The problem is every time I try to come off them to see if the pain from the disease has lessened, the withdrawal symptoms are so horrible I can't get off long enough to tell.

Sweats, fever, spasms, severe muscle pain, runny nose, sneezing, coughing...it's horrible. So I have not idea if the pain I experience is from the disease or the withdrawals.

Help?