Thank you both.
I could take a little walk although I may have to weigh up the risks. It's definitely worth considering as a way to potentially regroup. I work alone but my manager is usually able to allow me to be flexible with my work, so that if I don't get all the cleaning done on a Friday, I'm often permitted to come and finish off on a Saturday, which really helps me if I'm struggling.
Camden, I really like that idea about taking nature items and favourite photos of nature to work. I think I will also focus on anything that's already at work which is alive, ie plants. I think that could be very grounding. And nature sounds are a good idea too, I think I'll take my headphones tomorrow.
I may make some flashcards to remind me to breathe and to try to accept what might be happening rather than getting in a tizzy over it.