Maybe I'm not the best person to give advice as I was long term sick. However when I went back to work, my colleagues knew about my PTSD (I told them, we were a close team and they are friends as well). I would say if not all, maybe tell one person who can watch out for you. I would be in a meeting and all of a sudden a friend would turn to me and say quietly - 'breathe'.
I used essential oils to ground myself, lemon is my favourite as it zaps me back to the present, I would have some on a tissue to sniff or put some on my lapel. Also take regular breaks if possible. I would go and sit outside for a few minutes, I would touch the wall and register how it felt and look around naming things I could see. If it is not possible to go outside, go to the bathroom, just take time. Also I have a touchstone (a small turtle) which I can hold in my hand.
I admire that you are both still working. I was made redundant in May and now looking for work.
Take care ((HUGS))
KP