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.