yea man thats crazy, I have had many sleep paralysis type dreams or w/e, and actually hallucinated, I have seen demons and shit, and the house I was staying at was haunted to.
oxymoron out of existence dream, is when you're out of this world basically, sometimes happens after an an end of the world dream, and when you come to it feels like your body dropped on your bed, or your bed was floating in the air and it drops, I was only about 8-9 when I experienced a dream like that and still remember it like it was yesterday.