A powerfully effective way to manage anger is to focus on your breathing. As explained on the Wellbeing page of this site, breathing is the connection between the conscious and unconscious.
Inhale deeply for a slow count to 7 then exhale counting to 11. Repeat three times. This stimulates the relaxation response that helps dissolve away your anger. The more you practice the calmer you will become.
Use the calming breath the moment you notice the first signs that you are beginning to lose your temper.
It is also helpful mentally to go through past situations in which you have become angry and mentally rehearse remaining calm in those situations using 7-11 breathing.
On one occasion a teenager I was working with in a residential setting stood nose-to-nose with me shouting and swearing and telling me very unpleasantly what he thought of me.
My response was to use 7-11 breathing to remain calm while thanking him for being so open and honest with me, to respect his opinions, ask what I do or say differently in future.
It was not until the following day, long after he had calmed down, that we sat and talked about the way he had spoken to me. Whether he now thought it had been an appropriate way of communicating. Whether he believed he had expressed his feelings, frustrations and annoyances effectively and, if not, what he could do differently on future occasions when he wanted to let someone know annoyed he was with them and the extent to which he disliked them.
My reason for leaving it until the next day was to ensure all the physiological effects of his anger had worn off. Trying to talk to an angry individual soon after their anger has passed risks setting them off again as they are still physiologically arouses even if, psychologically, they believe they have calmed down. It was also important for me, and for you in a similar situation, to act as the responsible person and not instantly ‘jump in’ with criticisms, punishments or other attempts to lay down the law.