It was, quite literally, a terrifying experience, as I'd been jolted awake in the first place by a nightmare. When I saw the shit in my room that I saw in my dreams, I wanted to yell out in fear and retaliate towards it, but couldn't. The only thing that kept the experience from being scarring was my frontal lobe almost immediately refiring, allowing my to figure out that it was just a hallucination. I'd expect regular sleep paralysis to not be a big deal, but since this was a one-time thing, I was terrified. As for the hallucination, I'd finished watching "It" just before I went to bed