Sounds like a crawl space they to day I still hate them. If possible if you can set up a camera to record yourself sleep, may help figure out what is going on maybe, wish I could give better advice.
That’s what I was thinking too. The sound in the ears, the feeling of movement as on a boat. Could you be coming aware before your spirit is back in the body? The gray mass could be your spirit re-entering? Just some ideas. Idk about the crawl space. Do you think there is an entity in there effecting you?
After reading some about out of body experiences I agree, it sounds very very similar to what i experience. Definitely something to think about. It may very well be my spirit entering my body.
As far as an entity in the crawl space...I would be lying if i said the thought hadn't crossed my mind. I have had a few strange and sometimes scary experiences in this house. But they have been somewhat few and far between. So I can't be for sure.
Turning around and looking at it right now, though, gives me a bit of a chill. Bad vibes, or maybe just anxiety. Hard to tell the difference sometimes.