Humans don't laugh throughout the year. There's always a day to feel different. Some of this days are sad days, boring days, tired days, play days and so forth
Whenever you feel down either by sickness or by circumstances you don't need to stay down and do nothing about it.
just get up
Take a shower
Get some exercise
Chat with friends who could share you up
But if your house is boring, go out
Have fun
When you! return do well to make your favorite meal and sleep early
You will wake the next day full of strength