Sorry for the little gravedig but I had to post it. I've been experiencing something similar. I wake up in the middle of the night like I "forgot something to do and I have to do it now" but I don't know where I am, what day it is, who I am and I can't seem to move either.
I've had it for 2 weeks straight but it's been less now and I'm so glad it's less because that shit is crazy and terrifying.
So all those wanting to experience it : you don't.