I haven't experienced quite what you have but still I hope my feedback can be useful. As a child, I went through long periods of night terrors. Which in principle are quite different, because they are usually not lucid -rather the contrary, an invasion of a deeply unsettling dream experience into a partly awake state. The relevant part is how I understood better their mechanics when they manifested (thankfully, in much rarer occasions) in my adulthood. The trigger was unresolved tension and anxiety, related with loss of control, that seemed to erupt soon after drifting into sleep.
Some of the advice above is of course reasonable -making sure that for instance your diet is not contributing further to the problem, trying meditation techniques, or journaling to gather more insight about your dream mechanics in order to hopefully be able to alter them within lucidity or to at least modulate your response. But I understand that a core source of your anxiety is the helplessness that narcolepsy can bring, the dread that comes with the loss of control, and that dread I know well.
In my experience, there were two ways to fight this. One, which can be much more challenging for you, was securing my environment. And I don't just mean securing it physically, but rather sharing my fears with peers or family, which worked in a way as a partial delegation of that control and responsibility. Perhaps if you can make your surroundings more aware of your fear and challenges, the outcome will be less rough.
The second way, which is perhaps not that different, is to build some sort of protection. This of course depends on your practice and paradigm. For me, and for instance, protective fragrances helped a lot. A mist diffuser near my bed, or a bottle with some infused oil I prepared before hand, with a few drops of vervain, cedar or frankincense oils. Some plant spirits work well against nightmares, and I say this with a completely straight face.
