It's very common for us to all hold our breathes in times of stress. Even when excercising you can hold your breath. I realised I was doing it yesterday at Kung Fu when just balancing. If you try and take note today how many times you hold your breath when doing things you can begin to change it. Just breathe into those situations. That allows yourself to process whatever you are doing without holding onto certain emotions.
Read next
From @carface