I was diagnosed with sleep apnea 2 years ago (my colleagues convinced me to go to the doctor after I was caught repeatedly nodding off and snoring while sitting at my desk). My AHI was 105 - frankly, a truly terrifying score. I was used to tossing and turning all night, every night, getting what I thought was maybe an hour or so of sleep at a time. My body literally never fell into a deep sleep.
Not a big fan of the masks, but from day 1, I haven't had a day time drowsy problem since. In fact, even on occasion when I felt like taking a nap from a comfort perspective, I can't fall asleep, because I'm actually rested. The technician at my sleep study said this would change my life. He was not wrong.
For anyone new to the issue, I do recommend trying as many different styles and brands of masks as you can. I took the first one they fit me with because I didn't know any better. It was fine, and clearly worked. But last year when I went in for my update, I got a new style of mask and it fits me so much better.
In 2 years, there have only been 2 nights I haven't used the mask. Once was when we lost power, and once I was on an overnight flight home from Hawaii.
I do have quite a bit of weight that I should lost for many reasons, and I'm hoping as I work on that, it will also help with the apnea issue.