Courage to Drive Away Dark Thoughts

Lord, sometimes I think I am my own worst enemy. I constantly battle the negative thoughts that pervade my mind. Especially in times of hardship and suffering, I work unceasingly to cast out these pessimistic ideas. I know that this is evil itself hard at work to try and shake the foundation of my faith. Let me not even give such thoughts my energy. Let me not fear that such bad thoughts are sinful. Give me the courage and strength to drive these notions away with the help of your love and mercy.