It repels success. It robs you of peace of mind. It blinds and binds you. Anger can paralyze and keep you stuck on stupid. Anger expressed appropriately is only good if it mobilizes you to take action.
Some people deny and suppress their anger and some people express it too much.
Both are unhealthy and not advisable. Don't allow old hurts or disappointments keep you from living with gratitude, hope, joy, love, peace, forgiveness, faith and action. The past has passed. Be totally present in this moment, in this day, in your body, in your home, in your job, in your mind and in your heart. Write down on a piece of paper what you are angry about.