Dreams are places between sleep and the afterlife, where dreamers can go and get a glimpse of magical worlds and dance in the realm of endless possibilities.
When you're there you never want it to end, when you're here you just want to get back to there.
Nightmares are the end of dreams...but you're still there...aware that it's all coming to an end.
What you described Ms Riff does indeed sound like a nightmare.