Problem: half awakening

[Skeleon]

Wow, that's almost like locked-in patients (though they are like that the entire rest of their lives).
I had something like that on a (compared to yours extremely) small scale: I had lain on my arm the entire night and when I woke up, my arm was completely without feeling and immobile. Scared the hell out of me, I feared I'd suffered nerval damage because of oxygen-deprivation or something similarily permanent. After about half an hour, it went back to normal, luckily.
Yours sounds really bad, though.

 

[Yankmy Armoff]

i had a similar episode a couple years ago, lying flat on my back, completely unable to move (except my eyelids weirdly) and utterly convinced someone was sitting on my chest pushing down on my throat (i also have asthma so that was fun) and because thats what it felt like thats what i saw. waking up to someone sitting on your chest choking you and only being able to stare into their eyes is a very disturbing experience.

somehow i worked out i had to still be dreaming or similar and started trying to prove it to my brain, then i was able to move again and it turned out that my own arm was resting on my throat...

doh.

 

[neuromasser]

Happened to me few times. It's scary the first time, but really depends on your state of mind
Gintoki had same problems