Based on the information provided, especially your low oxygen saturation, your obstructive sleep apnea (OSA) is definitely significant enough to treat. The continuous positive airway pressure (CPAP) could result in an increase in swallowed air, with or without increased abdominal pressure, and thus could aggravate your reflux.
Having said that, I strongly urge you to work with a sleep specialist and his/her staff, to find ways to make the CPAP tolerable. You may have to go to the bi-level positive airway pressure (BiPAP) machine. And, it may take a long time for you to find settings that will be both tolerable and effective. Positive pressure is far and away the treatment of choice. You should give it a long trial, but not on your own. Finally, do not consider surgery at this time. The benefit is unpredictable and unpredictable side effects can be both dreadful and irreversible.
You should get optimum therapy for the nasal polyps to eliminate them. Make sure, even though it is unlikely, that none of the tonsil or adenoid tissue has returned.
check sleepnet.com.........its a great forum..good luck