Sad and short of breath? Avoiding this feeling won't make it go away.
The key insight of Buddhism around suffering are almost algorithmic:
1. Things change
2. Grasping for pleasure will cause suffering when things change (#1).
3. Pushing away adverse emotions (like anger) will cause suffering when things change (#1).
4. Be mindful no matter what impermanent state arises.
As you get more comfortable in the practice of meditation, diving into negative feelings and emotions (as opposed to pushing them away to cause suffering, as in 3) is one of the best uses of the practice. What you will find is that the light of awareness can help you to overcome these emotions more quickly… but only with careful practice.
The first thing to recognize is the angry rerun. This thought of repeating the harmful experience in memory and recounting the hurt is what renews the aversion at its maximum level. Knowing that this angry rerun is not mindful and focusing attention on it allows you to be mindful of the residual pain of the aversion constrictor.
Just like a boa constrictor, negative experiences constrict our breath, focusing the body on short, fight or flight choppy breaths. Muscles tighten. Vision narrows.
Notice this for yourself. Dive into the sensations in your body brought on by negative emotions. Do you feel tightening? A pit in your stomach? Is your breath constrained? Pour your attention into these sensations. Be mindful of how they, like any other sensations, dissolve.
What happens if you have a memory of the painful experience? Does the dissolution of the sensation reverse course and constrict anew? We must meet our challenges mindfully, taking the odd and counterintuitive position of exploring our pain to avoid the suffering of attempts at pushing away these experiences—the grasping for only positive states that cannot be maintained. Know thyself in every fleeting moment, whether it has a valence of good or bad.