If there was one thing I was going to stake my entire life on, not to be melodramatic (completely to be melodramatic), it would be my sense of humor. I'm fairly certain I've been funny every since I was a kid. I guess I should tell you that my first joke - Mama, please confirm this later on Facebook - was a pun. When I was around four years old, my family and I visited the Kennedy Space Center. When it was time to eat I suggested we go to the "lunching pad." See? I've been making topical jokes since before I even had a clear concept of a topical joke.
But, like The Force, humor has a light side and a dark side. Laughter doesn't always spring from joy; sometimes it emerges from the darkest times in our lives. Speaking from personal experience, humor has always helped me get through my worst times - I'm Jewish so it's practically genetic. Jokes aside, I do believe it's universally true that humor is healing. I don't suggest making light of serious situations, but I also recommend trying to find something funny within the gravity. If no one did that, SNL would probably cease to exist.
That being said, there's a fundamental difference between making fun of misfortunes, and finding humor within the worst situation. I got rejected from one of my top choice colleges, and it was devastating (I mean, I understand there are bigger national and global tragedies but this is my example). As I sat at the kitchen table simultaneously eating out of two separate Ben and Jerry's pints, I couldn't help but think how funny that image was. There I was, one spoon, two whole pints of ice cream, and swollen red eyes. Oh my god, this is was the super sad break up part of the rom com that apparently was my life at the time! By seeing myself that way, I was able to contextualize the moment in a new light. Yeah, it was terrible, I felt like garbage in that moment, but by finding something about that moment that made me laugh, I was not only able to soften the bitter blow of rejection, but also gave myself a way to look back on that moment with more emotions that "God, that sucked".
To quote Eric Idle (and all of Monty Python really), always look on the bright side of life. Even if the situation seems too grim to handle, find something funny to help. Even if you can't find anything funny in the immediate situation, go online and find a funny video, watch a Mel Brooks movie (watch a Mel Brooks movie anyway), do something that will make you laugh.
In all seriousness, start joking.