Let this sink deep in your heart: only creative people are happy. Happiness is a by-product of creativity. Create something, and you will be happy. Create a garden, let the garden bloom, and something will bloom in you. Create a painting, and something starts growing in you with the growing painting. As the painting comes to the finish, as you are giving the last touches to the painting, you will see you are no more the same person. You are giving the last touches to something that is very new in you.
Write a poem, sing a song, dance a dance, and see: you start becoming happy.