During the break, think / do something totally different from the issues that cause you stress.
Only after a while, then reflect on the causes of stress / stressors see how you can counter / avoid / handle differently.
Look at the big picture / macro-view & count your blessing / appreciate what you'd gone through / achieved - sometimes doing these can help you to de-stress.
Find a person to talk to / seek counseling - sometimes the person merely listening to you without any comment can reduce your stress.