Literally my greatest nightmare scenario. Nothing scares me more. Similarly, the jaunt is sort of the extreme version of this, and I try not to think about it x_x
Sometimes I have sleep paralysis (very rarely) and it's the worst, scariest feeling.
Sleep paralysis is scary. I haven't had it in 30 years, but I remember how shocking it was the first time. Curiously, in my case I also remember distinctly giving up and thinking "well alright, guess I'm going to die, wow" and being calm about it. Then the paralysis wore off.