It won't matter how many times you say I'm sorry, the wound is still there. A verbal wound is as bad as a physical one. I want to take this one step further. Even our thoughts of anger, though not heard by man, can be heard by Allah Ta'ala. We must think before we act and choose our words carefully.
Words are a powerful tool.
But this does not mean that anger is totally forbidden or of no use to humanity. It is essential for man's protection of self and property. Without it, he would be a coward, a victim of any evil, thief or invader. Anger regarding food, clothing, home and personal safety is good and natural.