I encourage anyone who [seriously] isn't happy in his or her life to exercise daily.
It doesn't sound like it'll help, trust me I know, but last year I had depression (not major, but depression nonetheless). I decided to take action by working out, and I believe that investment of time to better my self physically has made me grateful for my life. On top of exercise came eating right, and then after that came other means of mental health like meditation, and now I'm the happiest I've ever been.
Likely none of you are going to take something from this post, because a simple paragraph of text isn't going to make you take action in becoming a better person in your own life.
But if any single person does wish to be happy, truly you'll do what information this post gives.