I’ve had anxiety and social anxiety since I was about 13, and it’s always been more physical than mental. Most often the treatment for anxiety is cbt or mindfulness but it just doesn’t work because I don’t get the thoughts. I think a lot, I have adhd, but it’s just random things and never anxious thoughts? But my body will feel anxious, when I’m out of the house or socialising my heart goes fast, I don’t know where to look, I sweat, I can’t breathe, basically all the physical symptoms of social anxiety but I don’t get the thoughts. I just couldn’t do cbt for it because I can’t point out any self limiting anxious thoughts I have. 
I always do the counter acting stuff of thinking positively but it makes no difference. Same with stress, my body knows I’m stressed before my mind does. The worst thing is when I’m stressed I can’t eat anything, the smell of food makes me nauseous and I physically wretch if I try to force myself to eat, which makes things worse as I’m severely low on energy. I’ve just lost 7 pounds in 2 weeks from exam stress but my appetite won’t come back, and I don’t feel mentally stressed at all though!!