I have found that I am prone to sleep paralysis coupled with hallucinations when I am going through periods of heavy, regular drinking. Not sure why that happens, but it means I'll go through periods where I start to suffer from this consistently (almost every night) until I cut back. Pretty effective for keeping me away from alcoholism.

The standard format is 1) I can't move, 2) I'm filled with dread and 3) I start to see things, especially around shadows and objects in the darkened room.

Anyway, I'd say my worst two experiences have been due to particularly dark, terrifying hallucinations.

The first was waking up with the distinct impression that my bed was surrounded by dark, hooded figures. They did say anything, they didn't move. All they did was stand there. I don't even know when I was able to move again, I was too scared to try. Eventually my brain woke up enough to rationalise that this was my usual hallucination bs and I got up and switched on the light (as quickly as I could).

The second was worse. When I awoke, I had the distinct impression that something was in the room with me, but I couldn't see anything. Then I heard it - something shuffling across the floor, to the right of the bed. This went on for a while, with me just staring at where I thought the noise was coming from.

Then it whispered: "No one can save you"

At this point I was shitting bricks, but my brain still wasn't ready to snap out of it. I decided to just shut my eyes (to pretend to be asleep, I guess? Or maybe just desperate denial).

That was when 'it' climbed onto the foot of the bed, and loosely gripped my ankle through the sheets.

And that was when my brain finally let me nope the fuck out, jump up and switch on the lights. I am not ashamed to admit that I was letting out a fairly high-pitched squeal whilst leaping for the switch. Did not get back to sleep that night.