I recently started using CPAP and one thing I noticed in the sleep study, besides all the other reasons it was hard to fall asleep, was that when they were doing the titration test to find the best initial pressure, they set it very low and then let it climb up once I stopped breathing at that setting.

The problem was, I actually found it difficult enough to breathe through my nose at that pressure that I would just keep myself awake because I couldn't relax with the mask on. It was kind of horrible and my technician didn't change it for hours. Eventually I started just intentionally snoring while awake to try to get her increase the pressure. No idea if she did but eventually exhaustion won out after around 4 hours.

So just a thought, but if you're using an autoset machine (APAP) maybe discuss with your doctor and make sure the initial pressure is high enough that you're able to breath comfortably through your nose when fully relaxed.

And also, you can experiment with different mask types depending on your sleep position.