I also have narcolepsy and sleep apnea. There are sleep doctors that are either dentists or have a dentist that can fashion a device for you that positions your jaw in such a way that keeps your airway open. Make sure they give you the thing that you bite on after you take it out, though, to prevent jaw problems. A lot of insurance companies will not cover it, but, it is worth it. If this does not sound like a desirable option to you, there are also devices that you can put in your nose that cost about $10 on Amazon. I will put a link below. I have not used this because my nostrils are too small for it, but, my dad also has sleep apnea and refuses to wear the mask, so he uses it and it works wonders.
Edit: $15
https://www.amazon.com/dp/B078T7NRWM/ref=cm_sw_r_cp_apa_IA25Bb9WVQ6G4