When I was younger I had this more, haven't the last years at all. I used to have the evil presence type thing, it sat on my chest and choked me. These days I'm usually not constantly sleep deprived, I was back then. Stress and sleep deprivation can really set this off. Also I assume some people are just more prone to it. I also had exploding head syndrome, which is a weird name, because you usually don't feel your head exploding. I woke up rapidly by a bright light and a loud bang. First time I was a teen and I thought we had been nuked...

Even without feeling anything around you, it can be bad. It is like you try to swim to full consciousness, like if when you dove in to deep into water and swim up, up, and long for the surface to come.

Last time I had something like this I didn't even have paralysis, but maybe a sleep and awake overlap. I knew even after fully awake something bad but invisible was in my room. Took ages to calm down and go back to sleep.