The results of my sleep study are in. And the verdict is...

[Sleeprider]

Not sure I understand. Are you saying that you think my difficulty breathing while awake is unrelated to apnea? 

The way I feel while I struggle to breathe laying on my back awake, is EXACTLY what I feel in my dreams just before waking up and, often, continue to feel once awakened.

I was concerned that my problem wasn't related to sleep apnea because I can experience it regardless of sleep. The doctor didn't agree and mentioned gravity. 

I assume the weight of my own body crushes my airway a little. I'm not a heavy person though. 

I don't feel like my breathing is ever stopping but that the airway is becoming narrow when laying down.

Again, I automatically hold my breath while on my back because that becomes the most efficient way to breathe. It's too strenuous to breathe normally so my diaphragm takes a breath then rests up while regaining the energy to take another deep breath.

I think it could be apnea. I feel a lot of discomfort trying to fall asleep. My problem is obstructive sleep apnea.  The problem you describe could also be more serious problems.  Once you have tried CPAP therapy, let's talk  about it and see what your thoughts are. I feel respiratory obstruction before falling asleep, and it can prevent me from comfortably falling asleep.  My experience is to be very drowsy, and to fall into light sleep from which I immediately arouse due to apnea. I feel like a persistent post-nasal drip and obstruction is in effect anytime I try to sleep or nap with out CPAP.  It can range from a difficulty to initiating inhale, to a choking feeling in the back of my throat. Once I fall asleep, an apnea and sharp need to inhale will occur, sometime with an audible snort.  It's impossible for me to sleep properly without CPAP. Your experience may be different, but once you have used pressure for a while, we should compare notes.