Hi, Bob, and welcome! This is a fibromyalgia forum but we do have a thread about polymyalgia going. You would probably get a better response on that thread. Here is the link to it.
https://www.healingwell.com/community/default.aspx?f=24&m=934647&p=1
I tried to check out your medicine but not sure if you gave the right name. Did you mean prednisone? I have taken that for other health issues that I have. You might just need to give it a chance to get in your system. I only have taken it for short periods of time but it did help with inflammation.
Have you tried moist heat? Do hot showers help? It helps those with fibromyalgia. Some use a Bed Buddy. You can get these at Walgreen's and other places or you can make your own. Take a tube sock, fill it 2/3's full of raw long grain rice, and tie a knot at the top. Pop it in the microwave and it will give off moist heat due to the moisture in the rice. It does feel good on those achy muscles.
I'm sorry I can't be of much help but you may get more responses on the link that I gave you. Hope you start to feel better soon.
Sherrine