Don’t take life so seriously!
Learn to laugh at the little things and this whole “existence” thing will be a whole lot easier. Be amused by your mistakes and failures and be thankful that you learned your lesson and won’t mess up like that again. And most importantly do things that you enjoy! Life is not strictly business, it can be mixed with pleasure.
Think positive thoughts.
When you find yourself thinking a negative thought, stop it immediately by any means necessary. Slap yourself in the face, yell something positive at the top of your lungs or jump up and down. Do whatever it takes to get back to a positive mindset as such is essential for continual happiness and success.