Yup. That's a flashback. Or panic attack attached to a nightmare, as you're falling asleep.
LOL... One of my favorite things of all time was a friend describing "having nightmares while awake" and another asking "if they sort of came in flashes? Back to when it happened for real?" Nudge nudge cough, flashback, cough.
Lately most of my flashbacks have been about teeth. Not surprising since I need a cavity filled. (It's oweee.). I flash to when I was having my teeth broken, or when I was sprayed in my face/hair with someone else's teeth. Shudder. Super gross. Also nightmares with just one or two senses involved (why, oh why, do I have to be able to dream pain?), or true to life nightmares. Like once wasn't enough. Oh no. We have to repeat that memory over and over in full 3D anytime my brain is reminded of it. Pfui.
Which is a thing... If you were strangled? Having a sore throat from being sick (or even talking too much) can trigger flashbacks & panic attacks from being strangled. So can a chest cold, if you're having trouble breathing. One way to combat those types of flashbacks is to take care of the trigger (get my durn cavity filled, use some chloraseptic, get an albuterol inhaler even if it's only moderate congestion instead of albuterol worthy congestion, etc.)
Another way is abject mocking. ;) Flashbacks are scary or enraging enough when I'm in the middle of one & thinks it's real. I don't believe in giving things more power than they already have, so I like to joke about mine. Riiiiiight. Never the dream about the Rugby team, or when SAS came down, you pick the teeth? Hello brain. Priorities. Let's get them straight. Joking about my flashbacks & panic attacks may not have lessened them , but my recovery time is almost nill. Used to take me hours to "come down" off of a big panic attack or gnarly flashback. Thumbing my nose at them has taken it down to minutes.
A third way (which I totally suck at!) is grounding. I've never been able to ground myself out in a flashback (although I'm past master at grounding in panic attacks!)... Still trying to wrap my brain around trying to ground out in reality here, when I think I'm in reality there. Grounding over there, which I have managed to do, only makes it last longer /be & seem more real. Shrug. Still trying to learn this one.
There are other ways. These are just the 2.5 that I use.