Mist, and Dolfin have you tried acupuncture? It has really worked for me in the past.
If getting to an appointment is too much (like it is forme right now) sometimes rubbing the tops of your ears at the same time helps. Or focusing on your thumb and then your toe. Your thumb and then your toe.

These things can be calming in the moment. They can be very helpful.

Anxiety and PTSD are very tough to deal with I'm learning. Sometimes nothing helps. But some things do.

~S