Most terrifying thing in my life. I'm in the fog of a worn down opiate buzz, go into bed, then I start having a dream, I'm with my brother in some sort of big indoor gym, we're walking around, then we start going down this narrow hallway with wood panelling on the walls, then we get to the end and there is this room, just kind of like a waiting room in a doctor office, with a window you'd go up to and a door beside it, everything is very dark. My brother walks through the door, and then I just kind of felt like there was some evil presence or something, so this is the point where I get scared and start trying to wake myself up, but then you are in sleep paralysis. So then suddenly I feel like a ghost or something there is starting to strangle me, and it's so real, like you actually feel some hand around your neck, I'm screaming, and I don't know for sure, but I think you really do scream there half awake, then I can see, my eyes are open but I can't move and I feel like I fly up to the roof of my room, being strangled to death, and then just boom, you come to, and I'm sweating, tears in my eyes, just trembling in fear.
Just thinking back to it makes me feel a chill. I've had a number of experiences similar to this, they always occur, going to bed after having used opiates within say 2 or 3 hours of going to bed, and it always occurs around 30-60 minutes after falling asleep, from looking at the clock after waking up.
Another thing I think contributed to these experiences interestingly, is wearing earplugs while sleeping. I'm a pretty light sleeper and I live in an apartment with some noisy neighbours at times, so I used to always sleep with ear plugs, and I think something to do with that, being totally cut off from the sounds of reality, adding to your sensory deprivation and really letting the dream feel that much more real, adds to those night terrors.