SING!
Yes!
I am not talking about the songs that make you cry or the ones that make you moody or sad. I am talking about the songs that lift your spirits. They can be gentle or fast, just sing. Do you need to know that science backs this up?  (I'm told that the positive effects of music on the immune system can last for hours or even days!) Would you like to hear that there are those who believe that the Heavenly realms are made up of music. Does any of that matter to you right now? 
Sing or hum, make some music with your voice. Move some, bang on the table. Repeat.
Don't take my word for it. 
Do your own experiment. Chart the results if you want to. 
At least give it a try. 

Need ideas for a song to sing?
Try "Three Little Birds" by Bob Marley