Breathing trouble on airplane

I rode a plane for the first time recently and I learned that shit makes me feel sick! lol But on the trip back, I tried to keep myself asleep because the more I relaxed and slept, the less sick I felt. As I would fall asleep, I kept waking myself up because I would stop breathing. Like I would concentrate on breathing calmly and as sleep would come to me i couldn’t concentrate on my breath anymore so I would just stop breathing! It would only last for a second, but it is kind of concerning because you know, typically people don’t have to think about breathing to be able to breathe. Has anyone else experienced this or something similar? I would love to hear other people’s thoughts on this.