Thank you @johnbishop. I looked at that article and it was helpful and linked me to some other articles that were also helpful. I am very lucky, and managed to get an appointment with the vascular specialist next week, instead of “sometime in March” so maybe, hopefully, I will get some answers (?!)

Hi everybody. Another rare vascular disease that causes all sorts of issues is Giant Cell Arteritis (GCA). I was diagnosed with that in June, 2019, and had 3 days of 1000 ml I.V. prednisone in hospital, because I had lost vision in my right eye. Tapered on prednisone until November 2020, as well as started on Actemra November 2019. Taken off both in November 2020 due to WBC and neutrophils crashing. Back on Actemra every 2 weeks instead of weekly, the one treatment for GCA, and doctors are watching my lab work carefully.
Had 2 strokes in July and September 2019, a blood clot in left leg December 20, 2020 and a TIA January 22, 2021, so lots of worry for the doctors over so many clots, and why. Noted that I have a blocked carotid artery on right side (60%).
Has our member (I forget who it was that posted querying vascular issues) ever had GCA tested? Mine presented with the vision loss and I therefore had a biopsy of my right temporal artery to confirm the diagnosis. (That's the Gold Standard test for GCA.) I was hospitalized immediately following that procedure for the prednisone protocol, in order to save further vision loss in my good eye.
I hope this information might help. I've posted it before on other sites when members have queried various issues I've dealt with as a GCA and Diabetic patient.