Just reading this without context would make me say as well you should find another job. However, the truth is, no matter how motivated we are or ambitious, we all go through our ups and downs in the work cycle. No, matter how much you write your goals and tasks, it becomes a possibility. I would tell you before you quit your job, make sure nothing is going on in your personal life, take a vacation, and maybe think out why you don't want to do your work. You could be bored with it; you could not like your boss, perhaps you don't like the work.

Either way, call me; I have been there too, I can help you sift through things!