Turning worry into requests
In nothing be anxious, but in everything, by prayer and petition with thanksgiving, let your requests be made known to God. And the peace of God, which surpasses all understanding, will guard your hearts and your thoughts in Christ Jesus.
Paul wrote this letter from prison. He was not writing from a comfortable chair about other people's problems.
His answer to anxiety is not "stop thinking about it". It is to move the worry somewhere: out of our heads and into a request. Every anxious thought becomes something to say to God.
The part we skip
The phrase that's easy to miss is with thanksgiving. Thanking God while we ask reminds us of everything he has already carried us through. It shrinks the worry back to its real size.
Then comes the promise. God's peace will guard our hearts and thoughts, like a sentry at a gate. We don't have to understand how. Paul says this peace goes beyond understanding.
Try it today: write down three worries, turn each into a one-line prayer, and add one thing you're thankful for beside each.