Weird nightmare, and how do you describe a flashback before you know what one is?

Woke up from a weird nightmare:
I think I had been at work or something, but it was a congregate care setting. We were trying to hide from nuclear bombs, but the places we were hiding weren’t good enough, so between bombs we would switch up hiding places. At one point I saw an old lady confused and not really hiding well, so I pulled her with me under the sink. That wasn’t a good enough place, so we moved again after the bomb. The last place we picked was under some blankets. The dog that had been under there (a rottie I know from work) that we went to hide with, moved and went out into the open. The stranger I was with and I both screamed for him to get under the blankets but he refused. Then the bomb flashed outside. As the flash was fading, aliens dressed in military uniforms used a tractor beam to pull anything living, and out in the open,  out of the apartment. The dog dissappeared in the tractor beam. I stopped screaming, but the woman beside me kept screaming for the dog, so the aliens started to notice her and started to come over. I held my breath and tried to get her to stop, but she kept screaming for the dog. The aliens hadn’t exactly seen her, but they were almost at us… and I woke up.

Couldn’t go back to sleep after that. I had to keep repeating over and over that it was a dream. Funny how your brain can forget that, despite how absurd the dream may be… there wasn’t even any cold medicine I could blame it on last night.

I certainly had no hesitation in calling this a nightmare because I woke up afraid, but other times much scarier and more gruesome dreams don’t make any emotional dent, so I simply call them weird or scary dreams… I guess that’s a good thing though, right? (The few “nightmares”). The less-absurd dreams, the ones that might actually happen in real life, and make sense that way, I simply consider them dreams. It’s the off-the-wall, can’t-happen-due-to-laws-of-the-universe type dreams that I have an easier time calling nightmares. Oh, there’s also the flashbacks and memories that happen in my sleep, but I don’t often remember them in detail. Those I’m just left with emotional echos in the morning, so they don’t count towards anything. If I happen to remember them and they leave an emotional echo, then I might call them a nightmare, but lately I label those for what they are: flashbacks.

Before I know what flashbacks were, I used to call them “daymares” because they were as scary as nightmares, but they came while I was awake… I knew they weren’t happening at the moment, but I couldn’t escape them either. Weird how we can make sense of things any way possible before we really understand what’s going on… I remember trying to describe daymares to some people along the way, but not really knowing how to explain it. I’m sure at some point I tried to explain it to a therapist. I didn’t think they were true at the time, so I described them as something imagined/made-up. They were real scenarios in that they were not outlandish like nightmares often are (like tonight’s was). They were “normal” in terms of “laws of science” kinda things. I wonder if anyone I described them to thought they were hallucinations, or if they guessed they might be real. If anyone told me at the time, I don’t remember. I do remember some people looked at me with pity when I described them…