I've had them quite a few times, first couple were pretty intense, although I didn't see anything scary, I did think I was going to die because I couldn't more or talk, I would try to move and speak/yell my brains out but nothing, I thought I was moving a bit, trying to slide off my bed, but my arm twitched and I was right where back where I started, like it never happened. That tripped me out solid. I thought it was from doing mushrooms, but that was weeks prior.
I looked it up online after it happened a couple more times, and found out it was sleep paralysis. I doesn't really scare me enough to bother me because I know it's all in my head and I'm not going to get hurt. However when it happens it's pretty scary... The sound you hear like a heavy rhythmic whooshing and the kind of dark blanket that starts to overcome me is the dead giveaway I'm slipping into it, and if I squirm enough I can get myself out but it takes a bit of effort...
It has happened quit a bit over the pas year, I've been stressed though so i suppose that makes sense.
I'd like to have video of it happening to me to see what it looks like compared to what I think is happening, I'm always trying to move around, but think I just groan and moan my ex was pretty sure that's all that I did..