Hello @havana, Welcome to Connect. PMR can definitely be a challenge doing some of the things we take for granted in our normal daily lives. If you haven't already seen this discussion, it might be helpful:
-- Comprehensive Overview Of PMR: https://connect.mayoclinic.org/discussion/comprehensive-overview-of-pmr/

My PMR has been in remission for a little over six years now for the second time but both times it was active I was started at 20 mg prednisone and was pretty much pain free after a few hours of taking the first dose until the next morning. My pain level when I woke up in the morning was generally about a 1 or 2 on a scale of 1 to 10 and went away again after taking my next dose. Another discussion you might find helpful for tapering off of prednisone:
-- How to Slowly and Safely Taper Off Prednisone but ... no set rules.
https://connect.mayoclinic.org/discussion/how-to-slowly-and-safely-taper-off-prednisone-but-no-set-rules/
You mentioned you are new to PMR and currently at 15 mg tapering to 12.5 next week. Did you start at 15 mg? How long have you been on prednisone?