tu es ma raison d'etre, darling.

Well, it's so simple.

Find something you love. Your passion. Your raison d'etre.
Work at the instrument until you have calluses. 'Til it hurts to play the notes because you are pressing on the areas where your fingers have bruised. 'Til your mouth is swollen and your lungs are crying for a rest.
Sketch until you have charcoal running up and down your arms. 'Til you are coughing on the smoke it releases.
Read and re-read the lines until you cannot sleep without your voice reverberating in your mind. Until you start quoting the script. Until someone asks you a question and you end up answering with a part of the dialogue.
Concentrate on a story until you realize, several hours, days later, that you haven't slept in a long time. Write 'til you get tired and sick of the story. 'Til you're purposely making the lead character die so that you'll finally be done with it.
Dance until you have cuts forming along the edges of your feet. Twirl until you're ready to throw up everything. Until you're ready to give up.
Play something that pushes your physical limits to the point where you are ready to collapse. That forces you to work with your team and build a strong defense. Until your shins are cold and muddy with sweat and your dirty tears.
And there you go.

What happiness.