Flares can vary in length and severity for me. If I can catch it early and get a steroid shot, it can just last a day. If I don't catch it early, or there is a delay in my shot (weekend onset), then it can last 3-5 days. The fatigue seems to take the longest to resolve. I echo the others: talk with your rheumatologist. He/she cannot read your mind, you have to communicate.
Hoping you get relief soon.
MS