People who have had sleeping paralysis, tell us how it was?

You’re in a mental state of half consciousness and the world of dreams intrudes into the world of waking, often unpleasantly; I’ve never had a demon sit on top of my chest but I often feel a horrible sense of doom and fear, hear loud banging and breathing and see strange shadows that shouldn’t be, I try to yell out but can’t and feel as if I might drift back to sleep but don’t want to because I’m in danger and will be helpless.