"Lord, if it's not your will, let it slip through my grasp and give me the peace not to worry about it anymore." - however, if something is going to slip through your grasp it may require actively opening your hands
All of your days have already been written in God's book. When you go through a disappointment, don't stop on that page. Stay the course. Keep believing. You may be tired, discouraged and frustrated, but don't give up on your future. Our God is faithful.