As someone without narcolepsy, the description of cataplexy sounds a lot like sleep paralysis (which happened to me a couple times in my life), and so do the waking dreams.
I have experienced sleep paralysis several times, and I have always retained the ability to apparently feel my body/limbs as I think most people do. It would seem that the author's experience of sleep paralysis is different from most people's.
I have had multiple (thankfully rare) instances of sleep paralysis in which I am completely unable to move upon waking, with the classic feeling described in the literature of a heavy weight on your chest (presumably sleep paralysis is the experience from whence the Norwegian word "mareritt" -- meaning nightmare -- comes from; you are being "ridden" by an evil creature called a "mare")
The worst experience with Sleep Paralysis I had was paired with hypnogogic hallucinations of wasps flying above me. I was sitting there terrified and utterly helpless to move. None of my usual anti-cataplexy tricks worked at all.
Eventually the sleep paralysis wore off and I stumbled out of the room in my underwear. I cautiously crept back to see if the wasps were still there. Staring at the ceiling, I realized they weren't wasps, they were ... dragonflies? Then the dragonflies disappeared and I realized the whole time it was just a tiny hook in the ceiling, the kind of thing you'd hang a potted plant or decoration from.
This was all before I learned the finger trick for cataplexy, however. It's been over a decade since I had sleep paralysis, but next time it happens I will definitely give it a try.
Sleep paralysis has been more of a tree trunk experience, where I can feel everything and use my senses, but not move (usually paired with hallucinations).