Controlling thoughts or emotions is very difficult. It helps to understand why we get them in the first place.  What is in us that makes us think or feel in a certain way? How is another person 8n same situation behaving differently? Contemplating, meditating, or introspecting in any way helps to develop self awareness. This helps in creating some space to not act on negative thoughts or emotions. That is another way to control them. Don't act on them.