Hello @aewin, Welcome to Connect. You are not alone when it comes to being concerned about GCA symptoms. In both my occurrences of PMR my primary care doctor and my rheumatologist had my keep a daily log of my symptoms and pain along with my dosage of prednisone. They were always asking me if I had pain in or around the temples or scalp and if I had any vision symptoms which could indicate that I also had GCA. I was fortunate that I did not have GCA. I think you are right to be concerned and to advocate for your health. I don't have any experience with GCA but we have other members like @tsc @novabill @pickle7 and others who have posted their experience and related information in the following discussion:
--- Think I have Giant Cell Arteritis (or GCA): https://connect.mayoclinic.org/discussion/think-i-have-gca/

You might also find the following discussions helpful:
--- PMR progressing to GCA? Broken vessels in eye: https://connect.mayoclinic.org/discussion/pmr-progressing-to-gca-broken-vessels-in-eye/
--- How often does PMR progress to GCA?: https://connect.mayoclinic.org/discussion/how-often-does-pmr-progress-to-gca/.

Are you able to seek a second opinion with another rheumatologist?