I've learned that the flow of gratitude brings joy. When I am feeling low, frustrated, or overwhelmed I whisper to Jesus, thank you. At first it's just a word. But I say it again. And again. Before I realize it, thankfulness swells in my heart. The joy of the Lord rushes in.
Rejoice evermore. Pray without ceasing. In everything give thanks; for this is the will of God in Christ Jesus concerning you. - 1 Thessalonians 5:16-18