Hi @cakodra,
Please post about how it goes. If have to persuade your doctor to put you on a trial dosage of prednisone, you may want to stress how disabling the pain is. Undiagnosed, and feeling sore and stiff like the Tin Man in the Wizard of Oz, I tried to use a push down faucet at a sink in a public washroom and couldn't do it. The person beside me noticed and pushed it down for me.
The fatigue associated with PMR and GCA can be anemia - the anemia of chronic inflammation. That was one of my symptoms, but the prednisone corrected it.
I read about your blood pressure below.
I was on very high dosages of prednisone for a while. It did not effect my blood pressure.
Off it, my blood pressure was pretty low and doctor advised to eat more salt. My BP went up, still in a normal, good range, and I no longer feel dizzy when standing up.
Good luck,
Teri