simmer - To heat a liquid, usually a stew or soup, just below the boiling point, allowing it to cook slowly; or to stay in a slow, controlled state of progress or tension, often before a larger event or change occurs.
He was simmering with anger, but he kept it inside and didn't say out loud what he was thinking and feeling.
trauma - A deeply distressing or disturbing experience, especially one with lasting emotional impact; a psychological or emotional wound, often resulting from an intense or life-threatening event.
Childhood trauma can have long-lasting effects on a person’s mental health
