Walt Disney: “We don’t make movies to make money, we make money to make more movies.”Now substitute what you are truly passionate about for the word "movies". If you're not making money to make more "movies", then stop doing what you're doing and start doing that.
And here's the nice ironic twist. I guarantee you that if you make money to make more "movies" that you'll make more money. And you'll be happier, which is kind of nice too.