It’s a decision you make to not worry. Jesus said in the Sermon on the Mount. He Said: Do not Worry about your life!!! God has a plan for your life and it begins by saying don’t “Sweat it!!” 
Jesus said: Don’t Worry, it’s not going to change anything anyway. He says you can’t solve your problems by Worry so do not worry about your life.
People, it’s a decision we make. If you are one of those people who tends to Worry about things day in a day out Jesus said: Put this into Practice, STOP Worrying.
You make the decision to STOP Worrying. Worry will not leave your life instantly it won’t be absent for your life unless you kick it out! 
What you do is Pray instead, you invite Prayer in. And guess what? 
Paul said: Instead of Worrying about everything, Pray about everything, Cast those cares on the Lord, and then He said: And the “Peace” of God that passes understanding will “Guard” your heart and mind. 
If you’re going to “Worry” don’t “Pray” and if you’re going to “Pray” don’t “Worry…” its your choice !!!