Dreams. Reality?

Imagine a pitch black background. Everything around you is black.  It's like the ultimate black hole. 

There is a row of blocks. (6, maybe 7.)  One by one the blocks start falling downward into the blackness. At first starting off slow, and then progressively getting faster. You try to retrieve the blocks to re-attach them, but you are unable to do so quick enough.  As soon as the last block falls, you are shaken awake.  Inside, you feel like you're somehow not as alive as you were before. Like this was death and you came very close to it before you were able to wake up.

This was my childhood nightmare. I always knew it was a dream, but to me, it felt so real.