You have filled my heart with greater joy. (Psalm 4:7)
Sit comfortably, close your eyes, and breathe deeply for a moment or two. Allow your concerns to move across your mind and wait off to the side for now.
Imagine you are taking the bus from school. Because it is a rush hour you are stuck in traffic. This experience puts you in a bad mood. A friendly person smiles at you and puts you at ease. You nod a greeting as you feel good to find a friendly presence on the bus. This feel-good greeting turns your bad mood into a good one. Now it is your turn to pass this good feeling onto someone else.
Dear God, whenever possible and by your grace, turn all bad moods into good ones. Thank you for the people that you provide me with to help me in this process.