I started using a CPAP with a nose facemask almost two years ago. My doctor ended up also prescribing a low dose of Ambien because wearing the mask triggered a claustrophobia reaction in me. It was enough to get me to sleep with the mask on most nights, but I almost always pulled the mask off after 3-4 hours (or less) without even waking up. I haven't worn the CPAP for about six months because I have allergies that keep me just congested enough that I can't breathe through my nose with the mask on anymore. The thought of a full face mask terrifies me.
After all that, my sleep seems fine (it never seemed bad at all to me) and I have some amount of dependence on Ambien which I have no idea how to kick.
It's not about fixing poor sleep. Chronic sleep apnea causes other downstream effects like pulmonary hypertension and right-sided heart failure, which are the main things we're trying to avoid by using CPAP machines.
> It was enough to get me to sleep with the mask on most nights, but I almost always pulled the mask off after 3-4 hours (or less) without even waking up.
That's pretty common, but you get used to wearing the mask longer and longer, it may take multiple weeks. Me and a lot of users on /r/CPAP will give you similar feedback.
As for allergy congestion, have you tried Claritin, Flonase, others? May need to check with the doctor.
After all that, my sleep seems fine (it never seemed bad at all to me) and I have some amount of dependence on Ambien which I have no idea how to kick.