Letting go and letting GOD

Why is it so hard to stop worrying about things you have no control over???? I keep reminding myself, let God take care of it the way he sees fit, just pray about it. BUT, I find myself worrying about the outcome, thinking about what ifs and getting down about what the future may or may not hold. So, this is a visual reminder for me to Let Go and Let God. I will continue to pray for healing but also pray for acceptance of God's plan.