If your administration isn't as open to making changes or if you want to learn to distress on your own, there are ideas of what you can do on your own. I'm going to emphasize being able to keep your goals reasonable as well as saying no to people when you don't have the energy nor the time.
There are more ideas here on how to avoid getting too stressed at school. The key here is to leave school at school and make sure that those disappointments don't follow you home and interfere with your home life. Also, maintaining an organized routine in the classroom will help get back in the swing of things and allow you to go on "auto-pilot" for those moments.
Teachers TV also advocates for a line of communication between teachers and the administration to try to find a solution to managing teachers' stress. The school has a weekly Pilates program for the teachers every Friday, which helps releases stressors from being both keeping in shape as well as having fun with friends. There are also many other tips to administration about what they can do to improve overall wellbeing.
How does stress show itself in your life? It may vary from irritability, getting sick more often, feelings of depression, or even your body feeling more tense and tired. This article advocates for administrations to help teachers learn to manage their stress levels and schedule seminars focusing on stress relief.