In this post, I'd like to introduce you to one of my favourite metaphors for unhelpful reactivity -- the second arrow. The concept of the second arrow comes from a Buddhist parable, the gist of which is this: If you got shot with an arrow, it would be bad. It would hurt a lot and could be life-threatening. There are certain actions you would likely want to take immediately such as get the arrow out, stop the bleeding, go to the hospital, etc.
What would NOT be helpful would be to get, say, angry -- either with the person who shot you or with yourself for being stupid enough to get shot. If you did get angry, you would be in physical pain (and possibly mortal danger) AND, on top of that, you would be...well, angry, which generally doesn't feel good. So, not only would your discomfort have increased (pain of arrow + pain of being angry), but your anger would likely to distract you from taking the actions that would be most helpful.
In effect, it would be like shooting yourself with a second arrow.