Sorry to read about your experience. I'm just 52 and was diagnosed about 7 months ago. Before this, I'd had no notable health issues.

After the diagnosis, my rheumatologist initially prescribed 20 mg of prednisone daily for a week, then recommended that I tapered to 15 mg daily after a week. I continued to feel some pain but with much improvement after a week, but the weekend after my taper to 15 mg, I experienced excruciating pain, needed my wife's help getting out of bed, and could barely walk, which was initially terrifying. However, my rheumatologist then recommended that I increase my daily dosage to 30 mg, and split the dosage to 20 in the morning, 10 in the evening. He held me there for 4 weeks or a month, before recommending a slow, steady taper every 2 weeks by (as I recall) 5 mg daily until I got to 20 mg daily, then by 2.5 mg daily every 2 weeks until I got to 10 mg daily, then by 1 mg daily every 2 weeks until I get to zero. For me, the higher dosage and the split dosage with the taper above has worked well, aside from a single flare-up a couple of months ago. I'm now at 5 mg daily (3 in am, 2 in pm) and due to taper to 4 mg daily on Tuesday, and hopefully I'll be to zero in mid-February. I personally hate being on prednisone, because I hate feeling medicated, but the results are undeniable, and I do not want to experience another flare-up.

Coincidentally, and related to your question, I've also experienced irregular pain in my right knee (from an injury when I was 20) and in both shoulder joints sporadically over the past few months, which I've assumed to be PMR-related. I've seen an increase in the pain level recently, with the lower temperatures (I live in central Ohio). In my follow-up appointment with my rheumatologist this week, he advised that those pains are likely arthritis-related, not PMR-related. This surprised me, as I've had some joint pain in past years (before the PMR diagnosis) in the winter, but nothing quite at the current level, and not in the shoulders, as I recall. So good news is that the taper is working as planned, but bad news is that now I apparently have arthritis! I asked if the prednisone or PMR could aggravate or activate arthritis, and he said no.

I hear you on the "just getting older". Shortly after the onset of seasonal allergy season for me this past March, I woke up feeling initial PMR symptoms (tight and painful shoulders, hips, and hamstrings) and initially shrugged it off as me slipping on my fitness/exercise and "getting older". Even after a few weeks of exercising/stretching more, and taking ibuprofen at night, the pain kept worsening, and started asking more questions of my PCP, who eventually got me to a rheumatologist, about 6 weeks after my initial symptoms. I got pretty lucky.