I have both hips with their second prosthetics and many years of SI pain , bursitis and piriformis pain both before and after. Have had steroids, PT and chiropractic care.
The best and longest relief has come from icing and consistent stretching.
I lie on bags of frozen peas or corn. Once pain is under control, daily stretches- my ortho, PT and chiropractor all showed me different ones, and I eventually created a routine that works for me. And yes, it hurts like you cannot believe when you start-took me 2 weeks to see results the first time. If I get lazy and skip am stretching, or spend too many hours in the car, it only takes about 3 days to get back on track. Getting up off the floor is the toughest part.