Mirth & Melancholy, reminds me of the story of Pandora's Box. It held innumerable evils that were unleashed on mankind, but the Gods were kind, there was one more element confined in that ol' box, and when she opened it, along with sorrow and despair, there came also hope.
It's healthy to feel grief, and sorrow, to be momentarily attacked by free-floating anxiety, and to cry "Woe is me" in your bathroom mirror, but then it's time to smile and to laugh and just get out there and kick life in the ass. So when you're feeling down, remember -- the road you travel is well trodden, you're not the first, not the last, and not alone!
So whether you're in the mood for whimsy, or something more solemn, I hope you find the right salve for what ails you.