My situation is not as bad as yours but in the same area. For 2 years I tried to resolve groin pain and constant tendonitis in illiopsoas, and it band. Finally I am trying the injection. The injection is into the tendon which in my case is constantly rubbing against the implant. If it eases the pain and I can build strength in my leg and then it comes back, a second injection will be tried. If there are the same results then the tendon is cut. I did speak to the nurse and she said she had patients coming for up to 10 yrs for the injections. the steroid weakens the tendon but I think what's the difference if he is going to cut it anyway. She said you just don't want it to snap.
The walking upstairs, etc. in my case is because my leg strength has not returned regardless of PT, and will not until the tendon is resolved. Sorry long winded jane redbeets