I can’t believe you have the same symptoms I had. Mine started with “ feeling like I always just worked out for the first time!” Shoulders, upper & lower back in pain. My thighs & buttocks in such pain. It would hurt to stand very long, get up or off the couch and it was all I could do to roll over in bed.
I’m finally down to 10 mg prednisone today. But we have so much snow & it’s so cold that doing anything is exhausting me.
I took gabapentin for years. Worked well but then stopped. The drug you said starts with a pla? I have heard about it before.