I suffer badly from this, and have for many years.
All of the things you mention ring true. I get screaming noises in my head that build up until I manage to wake my body up, which is fucking difficult.

The most creepy and hallucinogenic episode I had was realising I was basically awake, but I appeared to be in a very scary version of my bedroom - a skanky dungeon type affair, filling me with a sense of foreboding. Scared shitless, but understanding what was happening, I ran to the wall and clawed a hole, through which I could see my real bedroom, and therefore my real consciousness. I forrced my way through theo hole and I was sat on my floor, cold and shaking.
( mookay immune to icons since, Fri 8 Apr 2011, 22:07, 1 reply)

Had this once
Days after my father died. It was horrific, worst night I've ever had
(TheCrownPrinceOfZanzibar, Fri 8 Apr 2011, 22:14, closed)

I rather inappropriately clicked I like this, but I meant to click reply....
Was going to say - apparently it can be triggered by stress or buggered sleeping patterns, so I can see why you were affected by it at that time.

For me it's actually getting worse as I get older, but there's no obvious cause. It's good for feeding my imagination though, although maybe its my imagination that causes it in the first place.
( mookay immune to icons since, Sat 9 Apr 2011, 13:44, closed)