do you have a copy of your polysomnograph sleep study results? If not contact the sleep center where you had the study and request one. Then read what your pressures were and go from there. We can guide you from there. Are you on any meds that would interfere with the machine? Find out, google is your friend. I would do a set pressure rather than vauto. Sounds like you are congested and need to address that first. Can you take an antihistamine?
They are probably nasal polyps. Nasal polyps are known to cause sleep apnea particularly in young, fit people such as myself. Sleep apnea associated with nasal polyps, or "CRSwNP" as it's known to ENTs, tends to be harder to diagnose by means of standard tests.
I have stopped cpap and commenced a disciplined regime of saline nasal irrigation via neti pot combined with twice daily flonase spray. My previous use of flonase was sporadic. I believe my sinuses may have been irritated from long-term exposure to bleach in my apartment.
If necessary, I will go on antihistamines. Regarding my sleep study results, I am still awaiting.
Update: I just learned about something called "inferior turbinate hypertrophy". I also learned that a deviated septum can aggravate nose-based apneas.
Based on the description of turbinates (bony protrusions in the nose), I now believe that the flaps I originally felt were in fact turbinates and not nasal polyps. While turbinates are a natural and healthy aspect of the nose, they can sometimes cause problems when enlarged. It seems that I will need to see an ENT doctor to confirm.
Nasal sprays and washes have been effective, but I continue to experience a post-nasal drip in the back of my throat, which continues to interfere with my breathing during sleep. Antihistamines appear to be of little help. HEPA air filtration seems to improve symptoms but does not eliminate them. Flonase and antihistamines occasionally causd nosebleeds, resulting in dried blood accumulating in my throat and causing apneas. Mouth breathing made matters worse by causing dried mucus to cake up inside my throat.
If CPAP doesn't seem to be working for you, I highly encourage you to see an ENT doctor and maybe even an allergist. That's my two cents.
Update: One of the main issues I seem to be having is the total closing off of one nostril, usually my right nostril, what might be referred to as total septum deviation. But it only happens while lying down, and often resolves the instant I sit up or stand up. I should definitely see an ENT, but my schedule is pretty packed right now. I'm not sure if this is a true deviated septum, or just a result of my behavior, such as pinching one nostril shut while blowing out through the other, wearing earplugs in only one ear (eustachian tubes?), or taking medications that dry out the nasal walls, causing them to stick to esch other.
I've gone off of all medications, namely flonase and claritin (most people only need 1-2 weeks of flonase, anyways), to see if they were "drying out my nostrils" and causing one side to stick to the other - sometimes dry, rubbery mucus would also clog my nostrils. Since going off medication, there's been no change in my sleep experience, neither better nor worse. I continue to use the neti pot every morning before I leave the house but not at night, since it was contributing to post-nasal drip.
I got the Wellvue O2 Ring oximeter. Apparently, my oxygen levels are definitely dysfunctional, but only sometimes, and there seems to be no correlation between my subjective sleep quality and the Wellvue measurements.