laughter is the best medicine
Laughing a lot is a very effective means of recovering from physical or mental injury. More generally, keeping a positive outlook on life will help combat negative emotions during hard times. I think the best thing for you right now would be to spend some time with people you can joke around with. Laughter is the best medicine, after all.
the best ˈmedicine
the best way of improving a situation, especially of making you feel happier: Laughter is the best medicine.