When your mood gets sour (or yes, dour), perhaps all you need to do at the moment is get some sleep.
It’s your body actually telling you to take a break and breathe.
But if you miss the subtle clue of your mood change, then you might end up seeing everything in a bad light. And that’s just because your need for rest keeps you from thinking clearly and seeing the good in everything.
Go get some sleep, my friend.
P.S.: I just did.