I cannot describe how awful it is. In an episode of sleep paralysis, I have been genuinely convinced that the darkest abominations of my imagination are real, present, and about to do unspeakable horrors to me or my sleep partner. The worst thing is that you feel that ordinary people simply cannot sense them, and you are powerless to do anything.
Let me tell you, it doesn’t help your fellow sleeper’s sense of security when you wake up screaming and trying to protect them from something they can’t see.