[depsypher]

I've had both lucid dreams (which was enjoyable) and sleep paralysis before. The paralysis was not a fun experience at all, and sounds a lot like what you describe.

It's apparently common enough that there's folklore around it: https://en.wikipedia.org/wiki/Night_hag

I've only had the sleep paralysis a couple times thankfully, and anecdotally the last time I had woken up in the middle of the night beforehand, remembered something I needed to do on my computer, took care of it in a dark room real quick, then went back to sleep. I suspect the sudden bright light and a bit of stress probably contributed to it happening.

[kelseyfrog]

I we have our own folklore about it too. I believe a good percentage of alien abduction experiences are in fact attributable to sleep paralysis phenomena. Alien abductions are as real to us as night hags we're to our predecessors.