Let the word of Christ dwell in you richly in all wisdom; teaching and admonishing one another in psalms and hymns and spiritual songs, singing with grace in your hearts to the Lord. —Colossians 3:16
Christians are to rejoice. To do that, you need only to think of the great things God has done for you. Then we are told not to be anxious, but in our prayers to make our requests known to God. In your biggest problems you have One to whom you can go; and before Him you can pour out your heart with the assurance that He will not leave you without an answer to that great problem. Then we are to fill our minds with those things that are good. They are mentioned in the Scriptures as being things that are true, honorable, just, pure, lovely, of good report, and of virtue. It is upon these things that we are to think. Live positively, not negatively. Once you learn that secret, God will have given you the victory.
You know what troubles me today, Lord Jesus. In faith, I give it all over to You and now praise You, knowing Your love will not fail.