I'll suggest you not to quit the job. I taught in a school and i quit the job because of the same feelings you are experiencing now. Now i regret doing it. Because i realized that problem was not in the job, it was in my mind. If you quit doing any work, it will make you feel even worse. Just take your time and think how you can cope with it (which i'm sure you can do). Don't let your talent wasted up beacuse of depression. You CAN make it.
Wish you good luck!