"Look job, it’s not you, it’s me. I don’t think we’re as compatible as I once thought."
I don't think I have read an article that explains the relationship with one's career better than this one. Kayla Cruz does an excellent job explaining why sometimes you need to leave your job to be happy; in the same way you sometimes need to walk away from an unhealthy relationship with your boyfriend/girlfriend.
My favorite aspect of this article is that it is very positive. Not finding your dream job right away is not a bad thing, it is just one stop on your career path. Kayla states that "It’s okay if you graduate and your first 'dream job' turns out to be an epic fail. CONGRATS! You’re one step closer to finding something you DO like...So don’t be afraid to acknowledge that what you’re doing isn’t the right fit for you and that you need something different. It doesn’t make YOU a failure."
No matter where you are in your career, I recommend reading this article.