Rocky,

Forget about the past, you can't change it,
Forget about the future, you can’t predict it,
Forget about the present, I didn’t get you one!

^ Double-y relevant, because it's your birthday!!!

*ahem*

When I'm in a slump, I like to listen to relaxing music to help clear my head, and maybe meditate a bit about what's bothering me. Exercise is also a great way to get happy, since your endorphins get pumping, and those are happy hormones. Finally, a good cry can do wonders, at least for me it can.