It is a medical fact:  Either you will learn to control your emotions or else your emotions will control you.  When your emotions are out of control, they will create havoc with your physical body.  David Messenger is a physician who has specialized in structural medicine.  Speaking of the effect of your emotions on your wellbeing, Dr. Messenger says, "Negative emotions are energy‑draining, mind stifling and completely counterproductive.  Allowing oneself to hang onto and revel in the bondage of bitterness, anger, resentment and hatred is a most self‑destructive way of living.  Bitterness, with its subsequent anger, resentment, hatred and then self‑pity, is the emotional disturbance I see most."