In order to decrease stress, you can't just "pretend" not to be upset by something while inwardly seething about the unfairness of the situation. You must actually develop the ability to be stress-free during challenging situations. This is what requires practice.
I tell my clients in every frustration, there is an equally positive lesson, gift, or opportunity. The problem is while we are focused on the frustration, we can't see the benefit.
The technique to lower stress is to take the emotion of stress, often experienced as anger, frustration, depression, anxiety, helplessness, and use that as your signal to start looking for the lesson, gift or opportunity within the stressor. This is more than just viewing the proverbial glass as half-full instead of half-empty. It involves actually finding how the previously perceived "stressful" situation benefits you.
This doesn't mean you will be dancing for joy but when you can find the positive value to the situation, then the "stressful" experience will be neutralized. You will be able to see both sides and it won't carry nearly the same stress level. Practice this exercise and you will be able to not sweat the little, and the big things in your relationship and your life! [To stay in touch with Kim, sign up for her newsletter at The Relationship Center]