I have had steroid shots in knees, shoulders and trochanter bursitis. The shots are for localized pain, very little is for systemic value. Osteoarthritis is hidden when on a high enough dose of prednisone. For me that's around 7-10mg per day.
I might suggest you go up to 5mg daily to see how much of your pain that controls. If that doesn't manage the pain try 10mg until you see your rheumatologist.
October is not that far away and it sounds like you started tapering immediately after starting the steroids rather than staying at a pain free level for 2-3 months. PMR is naughty and does what it wants. Steroids and other PMR meds don't 'cure' like and antibiotic takes care of a bacterial infection. PMR meds only help manage symptoms.