Contemplate This: A Peaceful Mind Generates Power, by Norman Vincent Peale
The chief struggle in gaining mental peace is the effort of revamping your thinking to the relaxed attitude of acceptance of God's gift of peace.
Simply tell the Lord everything that is bothering you.
Have you experienced a sense of release when you have been able to pour out to somebody whom you can trust worrisome matters that lay heavy upon your heart?
When you empty your mind to God, you receive peace as a gift from God.
Definitely practice emptying your mind of fears, hates, insecurities, regrets and guilt feelings. The mere fact that you consciously make this effort to empty your mind tends to give relief.
Immediately start filling your mind with creative and healthy thoughts.
Let pass across your mind the most peaceful scenes of a beautiful valley filled with the hush of evening-time as the shadows lengthen and the sun sinks to rest.
Let pass across your mind the most peaceful scenes of the silvery light of the moon falling upon rippling waters.
Let pass across your mind the most peaceful scenes of the sea washing gently upon soft shores of sand.
Speak peaceful, quieting words, and your mind will react in a peaceful manner. Repeat that word slowly several times.
Going about your day, use this line of the 23rd Psalm:
"He leads me beside the still water; he restores my soul."
Go about your day repeating this idea over and over gently.