I really like the St. Francis prayer: even if you are not "religious," the thought conveyed here is a good one.
Lord, make me an instrument of Your peace. Where there is hatred, let me sow love; where there is injury, pardon; where there is doubt, faith; where there is despair, hope; where there is darkness, light; where there is sadness, joy.
O, Divine Master, grant that I may not so much seek to be consoled as to console; to be understood as to understand; to be loved as to love; For it is in giving that we receive; it is in pardoning that we are pardoned; it is in dying that we are born again to eternal life.