Work
“Do what you love and you will never work a day in your life” – somebody else
Everyone needs an occupation. Something constructive to do to pass the time and hopefully receive something of value in return for the effort. Work can control and consume our lives causing an imbalance with love and play and thus be a source for unhappiness. Our work can also be the cause of frustration when we are not working at the level we want or simply dislike our work.
When work is identified as a source of unhappiness, one can make a change relatively quickly. There are instances where we are stuck where we are and must find more creative ways to make changes that at least make work tolerable: need health insurance, retirement benefits, no available jobs elsewhere, etc.
Love
Ah love! The best feelings come from love. The worse can come from lack of it. Volumes have been written from the dawn of time and volumes more will be written as long as the Universe exists.
Play
All work and no play makes you a dull person. Play is very important. Having an outlet for laughter and enjoyment is a necessity. Hobbies, sports, clubs, etc. Lack of play time can be a significant source of lack of happiness.