To never get angry is ...
To never get angry is a tall order for almost any human being. So when we see anger as failure, and we try not to be angry and fail, it is so easy to turn the gun on ourselves when our anger comes. We blame ourselves and put ourselves down for not being able to control ourselves. Don't turn the gun in yourself. Don't give yourself a guilt trip. We spend our lives learning anger, so we are not going to unlearn all the beliefs and habits which create our irritations, frustrations and angers in a few days, or even a few weeks. (though some who really do 'get it' can change that fast). So be easy on yourself.
Healing the inner scars, forgiving ourselves, transforming those habits, are all aspects of this inner work, and they take a little time. Be patient, be gentle and merciful with yourself. And if you do decide you want to forgive and heal yourself, if you do decide you don't want to be a slave to others words and actions, if you do decide you want to be free of your negative feelings, one of the secrets is not to fight or struggle with those old habits. Accept them when they come, for whatever reason, and you'll be amazed how quickly the habit of those feelings is dissolved.
All healing begins with acceptance, including the healing of our feelings.