Misery is a beast that needs slaying. Lurking in the depths of the cavern at the edge of the forest (the cavern is you), misery sits in waiting, its teeth dripping. What you need is a big misery-killing sword. Mine are usually made of comfortable clothing, which may not sound like the most effective material for a weapon, but trust me - it works.
So, you get your sword. You can make it out of whatever you like. Boyband member? Cup of tea? 6ft troll doll? Sure. It's up to you, and you know best about your own sword. Once you've got your sword the best thing to do is to adorn it with a lot of jewels. This could be an item on any list of tips, but really, add some jewels. Each jewel should be formed from something encouraging or good. That one time when you had a sandwich, for example, and it tasted very nice. Put that on your sword in jewel form. Put every cute cat you have ever seen onto your sword as a jewel. I'm not sure what kind of a machine can actually perform that task, but just do it.
With enough jewels, your sword will be ready, and then you'll have to venture out into the dark. I know, it seems scary, but when you've got such a cool sword you'll have no problem at all (mostly because the jewels will be glistening so intensely that visibility will be much improved).
Remember, a bad day doesn't mean a bad life. Go get your sword.