Yes, taking deep, slow breaths help me when this happens

Yes I can relate. It happens when I’m in trying to fall asleep and I focus on my breath too much. It really helps to distract yourself from the thought of breathing. I sometimes think of a good memory and start describing (in my head) all of the things that I remember from that memory. Then I forget about the breath & fall sleep 🙌

Idk if it's the same but I often take big gasps air, followed by a sigh. People think it's because I'm annoyed but I'm really just breathing because I hold my breath to focus sometimes.

Yes happens often I usually space out at the same time and people assume I'm not listening when I actually am.