About a year and a half behind you, so you are a pioneer for me! Hope you are doing well....
Almost made it to 88 with nary a dx or tx. Happy Birthday in February of this year included GCA dx and beginning Prednisone. tx. Weird experiences both. Next Monday April 28 I begin monthly Actemra infusion for a year as well as going on the fast track Prednisone taper. Will see what happens. Like you, I am active (e.g.,a staff writer for our 142 year-old hyper local independent weekly newspaper Wet Mountain Tribune, many physical projects at the ranch, walk everywhere I can, etc.), mediate twice daily, For 35 years or so, have used mineral and vitamin supplements as do you; mine include: B12, C (I know it's been discredited, but I still follow mega dosing promoted by Linus Pauling; one thing for sure--creates expensive urine!), CoQ12, Ginko Biloba, Lutein, a probiotic, and a men-over=50 one a day....Like you, waaaaaay cut back on sugar, lotsa fruits and veggies for decades, but unlike you, use gluten free here and there but also ordinary breads (some of which I bake) and pastas, and have maintained decades habit of a Pinot Noir wine in the evening....
Don't know what lies ahead....of course pain free while on Prednisone protocol, not sure what to expect as Actemra kicks in, prednisone kicks out....