DD "crashing" at night?

I think all of us have experienced the difficulty of sleeping that often MDD causes, and I'm not an exception. But even when I'm able to sleep normally, this thing happens: when I'm in a pre-sleep state, my imagination loses its logic and starts to go random, like a computer that crashes: DD Me and my characters start saying and doing random nonsensical things and talking gibberish, random people and stuff appear, etc. It never turns really creepy though, or if it happened I don't remeber it. It might be annoying just when I'm ill or stressed. I mentioned "pre-sleep" state, but this actually starts to happen in the moment before I'm half-asleep and I'm still not numb. Weirldy, instead of being a bother, this thing sort of conceals my sleep: it's only when it doesn't happen that my DD doesn't let me sleep... And there's another weird thing, even though it happens quite rarely: sometimes this randomic DD is kind of "noisy", and at a certain point I hear something in my head. It's a sort of brief "crack" noise that brings me to reality, before falling again in the pre-sleep.