As a child, adults often tell you not to cry, to ignore your sadness. Culturally speaking, we are taught to avoid all unpleasant emotions. At any cost.
So, our impulse when we experience strong emotions is to escape them. We might do this by drinking too much alcohol, taking drugs, staying busy, emotional eating (or restricting food), smoking, and a number of other behaviors that harm us.
Negative emotions often feel stronger than others. When you are dealing with heartbreak it feels as though the world is ending. No pain has ever felt so concentrated, so deep or so agonizing.