What is the one symptom or complication that is most troubling?

@SleepingBeauty yes I experience burping and bloating. I have never had bloating in my life. So frustrating. 

Insomnia, is this a usual side effect?

I have gas and bloating 

@fowlerb777  I have not slept well since my heavy radiation for Prostate cancer, if I go to bed at 8pm I wake up at 9:15 to go to the bathroom and so on thru the night

I use biotene at night to help with the dry mouth. It usually lasts four to five hours and is helpful. I use a full face mask and replace it once a month as toward the end of the month it begins to wake and then I have to tighten the pressure. I also have marks on my face especially on top of my nose. when trying to fall asleep I find that I do a lot of yawning which creates a lot of pressure against the inside of my ears making my head feel very full and uncomfortable. If I can get to sleep without yawning I don't encounter that experience. I do not wake up feeling rested. The machine is better than no machine. In a few months I may be looking into the inspire implant. I am tired of being tired all the time my life show has changed since all of this sleep apnea stuff began a few years ago. I wish you all best and that you all have a healthy happy New year. Linda