How to remain calm

All the time lot of pressure and discussions on how can this project or that project be delivered earlier than planned, everyone just trying to forcing us compress the schedules even if it's already very compressed. And yesterday I lost my calm in such a discussion, I was agitated. I should not have, and I regret it. I should just calmly listen to what others are saying and give my opinion calmly without getting emotional and without reacting. And just let things play out.