Okay this sounds obvious but there's a few things we want to cover.
Your ability to know when you're holding your breath will also reveal a lot about where you hold stress in the body and what events during the day cause these discomforts. Start becoming aware of those moments throughout the day when you're not conscious of your breathing, when it's shallow or when you are in a holding pattern. Then notice if your face is strained, jaw tight, butt clenched, shoulders are up, etc. Then take note of what you're doing in that moment that caused such a scene and take a few long, slow deep breaths.
Speaking of long, slow deep breaths the next time you want to lash out, react harshly, scream at the kids, speak before you've truly listened to the other person, or your hell bent on being "right" in an argument; pause and take some long, slow, deep breaths.
Deep breathing calms the parasympathetic nervous system. A balanced nervous system is good for a zillion reasons including your mental, emotional and physical health. From cortisol level reduction to boosting your immune system, you do not want to underestimate the power of breath.
Lastly, we highly recommend looking up different types of breathing techniques - Ujjayi breathing and Kapalabhati breathing are fantastic stress relievers.