Hello. You did not show the text to which the question refers, which makes it difficult to answer it efficiently. However, I will try to help you in the best possible way.
Wiesel fought the trauma he had through activism, where he established actions and programs that fought injustices around the world. He used all the pain that his story caused to promote peace in the world and when he saw that his institution managed to achieve these goals, they had great comfort, because he saw that his works and actions were fighting against what made him suffer, the injustice and intolerance.