Stop and pay attention to what your body is feeling when you have these sensations. Notice the feeling, acknowledge it, verbalize it, accept it. Let your body feel and process it instead of fighting or distracting yourself. Let it happen until your body experiences it and it subsides. This is about retraining your central nervous system system.
There are a ton of methods and theories that fall under a heading of somatic healing…dealing with your body as it holds these things.
http://pete-walker.com/13StepsManageFlashbacks.htm
https://www.youtube.com/watch?v=ZoZT8-HqI64
https://cptsdfoundation.org/2022/06/27/the-tragedy-of-never-feeling-safe/
This happens to me often and boy is it intense! For me… I just acknowledge that I am having a moment… it’s like waiting for a train to pass. Some trains are short and other trains are longer.
For the long train, I sometimes will go grab me something to drink and maybe grab a snack and go read a chapter or two out of a book that I enjoy.
If you have a companion or close friend or family member that understands your condition, go tell them that you are having a moment. Sometimes my girlfriend helps me through it by letting me tell her what part of the movie is playing. That seems to help a lot but if nobody is around, I just try to get comfortable and I verbally assault the air around me until it’s I feel better but that’s not healthy, I just don’t know how to fix it.