Sorry to hear you are having a bad day. I know what you mean about the weather. I made myself a root beer float for dessert and put on a funny movie to 'lift' my mood. Hope tomorrow is better...
Go treat yourself to something small, even of its just a walk to the corner store for a chocolate bar. The natural endorphins you'll get from the walk will help elevate your mood, and then the treat will help too. You deserve it!