Avis, I understand that this will be a challenge for you (probably, because you say you're exhausted) but I would ask you to do something...not for me, but for you.

In case this is novel for you, go to apneaboard.com, a site in which membership is open, but free, and in the black marquee at the top of the page, find OSCAR. That is a freeware, completely safe, used by literally millions, that you can download, register yourself in, and then extract your SIM card from the slot on the side of your machine and download all the data. This might take a few minutes if there is a substantial record to be loaded into OSCAR. From there, continue to read the instructions provided by the authors of OSCAR about how to configure it for best results. Then, look at your 'events' record and learn what kind they are, and how frequently they come, but also how long they last. It is those events lasting at least 10 seconds that your machine will note, and OSCAR dutifully list in turn.

What I am concerned about is that you may actually have, or have developed over time (often this happens as a result of PAP treatment...if you can believe it!) either complex apnea or 'central' apnea, either one. These need a special regimen that often cannot be provided by a simple PAP or BiPAP machine. You might need an ASV (adaptive servo-ventilator). No matter which type of apnea you have, or if you have UARS (upper airway resistance syndrome) you can have many hypoxic events each night, some of them lasting 20-40 seconds, in which case it's no wonder your SPO2 levels show serious drops. Those are very hard on your heart, but they also arouse you each time you gasp and start breathing again. These arousals disrupt good sleep quality. In turn, you will absolutely be exhausted with brain fog, cognitive and memory impairment, be error-prone and even get involved in serious accidents.

PS - If you elect to do this, be sure to remember to install your SIM into the PAP machine when you're done.