SLW, sorry to hear about the health issues.
I had the sleep study ten years ago, and could not sleep during it!
I found the breathing masks unable to work for me as I would wake up with allergy related sinus congestion and I would be gasping for air. Which would cause more sleep interuptions.
So now, I just deal with it.
Just last Friday, a medical doctor mentioned the words "sleep apnea" to me...then asked "who I had for insurance" all without taking a breath...LOL