Comment by outworlder

> as soon as I try to go to sleep I feel like I’m being smothered and my heart starts racing

You may need your pressure adjusted. You are awake so whatever pressure the machine is using is fine. Then you start falling asleep and that's when your apnea kicks in.

If you are using the standard autoset 4-20 setting it may not be enough. Ideally this would be done by a medical professional and yada yada - insert standard disclaimer here. I would suggest increasing the lower pressure (say, to 7) to see if it helps you. I was using the default for years and, while it did help me, apparently it wasn't enough. After increasing, it's been night and day.

It _could_ be an issue with your mask but given what you described, probably not.