self-control

• Bite your tongue

  To deliberately and often painfully stop oneself from saying something, usually something critical, rude, or inappropriate.

• Pull yourself together

  To regain control of one's emotions and composure, especially after being upset or distressed.

• Stay calm under pressure

  To maintain composure and make rational decisions when faced with a difficult or stressful situation.

• Maintain one's composure

  To remain calm and in control of one's emotions, especially in a stressful or difficult situation.

• Keep one's head

  To remain calm, rational, and in control of one's emotions during a difficult or stressful situation.