Frustration

Frustration occurs when you feel out of control. So when you feel frustrated, take a deep breath and ask yourself: "What can I do to change/alter/influence the situation?". The answer is not always obvious and sometimes there is nothing you can do, but even just realizing that you can choose to let it go and leave it, instead of stewing over it, is better than being stuck in the frustration.

If there is something you can do, do it. And if not, let it go. Both are actions and both will make you feel better and dissolve the frustration.