Hi Neddy:
I fortunately never experienced problems not being able to breathe as I was falling asleep. But, when I first developed GERD three years ago, my main symptom was not heartburn but rather bronchitis and asthma. I developed wheezing and would catch my breath due to irritated bronchial tubes. Unkowning of the source, I went to an ENT doctor complaining of the wheezing and also the fact that I felt as if I had water inside my ears. The ENT doctor said I probably had reflux, but treated my asthma-like wheezing with a bronchodilator (one of those you puff on demand) and Singulair to help dry up all the gunk. The bronchitis and ear fullness went away with the Singulair but then I began to experience the heartburn, and the rest is history.
The reflux could be causing asthma-like symptoms that can certainly feel like you can't get enough air when you are laying down. You may also have sleep apnea which may not help the situation either. You may need some type of rescue medication you can use as needed when you feel you cannot breathe.
The other thing I have done is to have one of those steam machines next to the bed at night. Like the ones you put in babies' rooms when they have cold. They keep the air moist and really help when you have a cold or are having trouble breathing for any other reason.
Rose