Prednisone is very erratic. I also have an autoimmune disease and have been on 5mg/ daily prednisone for 4 years. You have to ween off slow, I didn’t and twice ended up in the ER. My Rheumatologist designed a reduction plan that continues for 5 months. I stay at each level for 1 month. I plan on trying after I’m recovered from Covid and Pneumonia!