Looks like glycerin is the active ingredient for it. Maybe try mixing your own?

18% glycerin and water, maybe a tiny amount of mouthwash for flavor? Add some xanthan gum if you want to make it a gel.

Users who own that pack report they get about 4 hours of runtime with a 40w load. I couldn't find any hard numbers on what the Auto A-Flex draws in terms of power, but with a heated humidifier it will probably be 60-100w, which would drain that battery faster. I'd say look for something larger, this...

Sounds very much like you woke up because you weren't breathing. Pounding pulse is a common symptom of that.

Have you woken up with headaches too?

I'd strongly recommend getting back on your CPAP.