On the mornings that I wake up in pain after a disappointing night (that it feels like resentment, sadness, or squirreliness is irrelevant - it is pain that expresses it self in whatever way. The fact that it is pain that I am experiencing is the point, as far as I am concerned), I find that by the time davening is over I am a new man. I have agreed with myself to let go of the comfortable and familiar resentment, anger or dashed-wishes I woke up with, and just go and daven to Hashem that I be with Him at least some of the time today and useful at least a bit today... I daven especially for my wife and children to have a good day - more than I daven for myself. "To heck with me - what can I do for others?" is a precious (and occasionally indispensable) attitude for me.