Hi Martyn,
I remember feeling terrified in the beginning. I was overwhelmed by the unknown so I started reading everything I could.
As time went by (dx'd April 2025), I've become more sanguine about my PMR realizing that I can't change the diagnosis. I spend my time now not even thinking about it. Or thinking "it's okay." This change has made me feel happier and as a result, healthier! Let me know how it goes for you. I still get bummed out at times.