Glad you found us
Many here are not using any of the fake meat products that you mention. I have not. It's actually preferable that you don't, from what I understand, as those are highly processed foods, and this way of eating leans towards whole unprocessed.
I think I have bought and eaten tofu just once but found even that wasn't necessary for a healthy McDougall diet. If you are concerned about getting enough protein, just do some reading around this site and forum, and you're concerns will be eased that whole foods starch based that is promoted here provides adequate protein. Plenty of GF people and recipes available here, too.
I too was shoved from doctor to doctor, tried to be put on this med and that, and had a heck of a time trying to get a diagnosis. Finally steroids were in my future when thankfully I discovered this way of eating and it has helped me so much--haven't had a real PMR flare up in several months!
My body has definitely healed a lot and is healing still since I began the diet early last fall.
We currently may be the only PMR people here, but there are quite a few managing other autoimmune pain conditions successfully with this diet. I can point you in their direction if you would like. And here is a link to my journal here if you want to take a look:viewtopic.php?f=21&t=27656
It doesn't chronicle my entire journey but will give you a good idea of where I was less than a year ago and how far I've come since then.
Please continue to work closely with your medical professionals. The vision issues associated with GCA should not be taken lightly.
Hope this helps some. Welcome to the board
PS Dairy has turned out to be my worst offender, which seems to be a common theme among us autoimmune folks. It took a strict elimination diet last fall to determine that plus my other food triggers. You can do a google search to find links between dairy sensitivities and inflammatory arthritis, including PMR symptoms and lupus, doesn't seem to matter if the milk is organic. It's definitely something to research and consider.