There is a popular prayer, known as the Serenity Prayer, that goes:
God, grant me the serenity to accept the things I cannot change, the courage to change the things I can, and the wisdom to know the difference.
Now regardless of your own personal affiliation with prayer, there is a perspective those words give that provide an immense amount of direction AND relief.
Control what you can.
Let the rest go.
Might be worth a try huh?