reverse nightmare 

When the nightmare is actually waking up to reality.

Reverse nightmares are usually followed by the chest-crushing realization that it was all just a dream and the dreamer must readjust, yet again, to the grim reality of waking life.

The most common of these events usually deal with someone's permanent absence (whether through death or break-up).

''I was dreaming mom was still alive and everything had been a huge mix-up.''
''God, I hate those kinds of reverse nightmares... they just make it that much harder to get over the pain.''

reverse nightmare by madcopy March 11, 2013