1) Listen to your favourite song from when you were 17. On repeat. All evening. It may be angsty but must be up-tempo. Give no thought to how uncool it now seems. Back when you were seventeen this song was the shit and you knew it. The zeitgeist is for idiots.
2) Dance to the aforementioned with joy and abandon all over your living room. If you get tired you may switch to a slower song (again, only if you listened to it as a teenager) but you should continue to gesticulate emotively along. If the ballad in question is of the middle-of-the-road-American-altrock genre then all the better. Something about losing a woman, or a horse, or a bet, or sanity is ideal.
3) Look out your window and notice that there's an amazing fireworks display going that seems to have been put on just for the betterment of your mood. If the world fails to comply with this imagine one. Or stage your own. Buy some sparklers. Set a cushion on fire. Set yourself on fire. Whatever it takes, honey.
4) Have some cake. I'm not talking comfort eating a whole fucking Kaesekuchen here, just to be clear, about a quarter should suffice.
5) Remember that you live in a world with the following: cake, tea, plain chocolate digestives, Dolly Parton, Barack Obama, blueberry pie, white russians, Margaret Atwood novels, Shakespeare, Ryan Gosling, your friends, your family, your pets, Ikea (particularly the meatball section of Ikea), the National, the Guardian, William Faulkner, Katy Perry (feel free to skip La Perry if she don't do for you what she does for me) and countless other amazing things and people and ENTITIES.
There now, don't you feel better. I do.