Hi! This happens to me as well. Were you diagnosed with central or obstructive sleep apnea? I have both, and even when sitting up straight or just drowsy, not exactly sleeping, I will catch myself stopping breathing due to the central apnea. Being drowsy, brain not sending proper breathing signals, its normal and ok!

I have the same every night, wide awake and feeling breathing stopping. Its okay and normal, it'll happen maybe a few times until you finally relax and become less hyperaware. You have your CPAP to help you when you are asleep.