You have to like what you are writing before anyone else can. Forget the grade, the publisher, the stats and just write because you love to write.
Stephen King's advice, however, doesn't just apply to writing, it applies to life.
Whatever motivates you, define it. Then, write it down so you can look at it when you feel a bit lost. This is your guiding light, the north on your compass.
Perhaps the solution is in making writing a part of life instead of a luxury in life, making it a habit instead of a hobby.