I worry so much. What can I do to stop worrying?
Fear, worry, stress and anxiety are not from the Lord. If you feel these emotions, you are not fully trusting the Lord to handle your troubles. Every person struggles with these feelings when he should relinquish a problem into the Lord's care. When relying on one's own strength, fear and doubt arise naturally. But, when you truly cast your cares upon the Lord, you can rest easy in His comforting arms.
Even if you don't mean it at first, verbally turn your worry over to God. Speak the words, "Lord, I give this issue in my life to You. I place it in Your keeping for I know that You are in control." Then, every time worry and doubt begin to creep in, say those words again. Eventually, you will find that you have to do that less and less.
Then, take it one step further. First Thessalonians 5:16-18 says, "Rejoice evermore. Pray without ceasing. In everything give thanks: for this is the will of God in Christ Jesus concerning you." Why would you want to thank God for your problems? James explains it this way, "Consider it pure joy, my brothers, whenever you face trials of many kinds, because you know that the testing of your faith develops perseverance. Perseverance must finish its work so that you may be mature and complete, not lacking anything."
God has a plan for your life and, sometimes, He must work out that plan in you through adversity. Are you willing to let God mold you and shape you according to His will? "Cast your cares on the Lord and he will sustain you; he will never let the righteous fall" (Psa. 55:22).