Whenever I am feeling all depressed or unwell in any way, my parents have little theories about what I could do to feel better. And, in the end, it all comes down to this.
Mom: Brush your teeth and take a shower. Everyone feels better when they're clean. If that fails, pray. If that fails, it's probably the aliens and you're doomed.
Dad: Drink a glass of water. Go for a run. Did you drink the water? Damn, well...you're probably just dehydrated. Have some more water. But don't have Gatorade, that has sugar (and hence calories)...plain water is best. Did you know the human body is 70% water? Here, I got you a glass. Once you drink that I'll take you to 7-11 for a Super Big Gulp. But only after you go running.