Smiling on the outside. 

There are 2 spheres of reasons (rather than specific reasons) you're staying in a job/career that's wrong for you.

Fear

Fear gets a bad rap, but it's not always unwelcome. We need it! Fear moves you out of the way when a car is going too fast and too close. And if you're afraid of making a big change, potentially disrupting the stasis of your life—this just means you're human.

To be honest, fear is almost always playing some kind of factor in keeping you in your job, career, or industry. That's okay, do gauge where it's coming from, and how it shows up. Fear is a trap that has many faces. Getting to know them all will save you a lot of time and anguish.

The real problem is letting your fear—of change, failure, of admitting that you're really unhappy—get in the way of your growth. That's not being human; that's keeping yourself playing small.

Unclear

OK, you're feeling some fear. But perhaps you're also just unclear about your true feelings. If you've read this far, you're probably not happy at work. Knots in your stomach might be the norm; anxiety and mental chaos are constant friends; you're suffering from insomnia. It's amazing how much fear can fog your thinking and cause you to ignore messages your body is sending. 

Getting clear takes courage, time and effort, love. If your coping mechanism is packing your calendar or like, deciding this is the time to finally watch all 6 seasons of Breaking Bad, the fog will persist. Clarity comes from enactment, not thought—and certainly not denial.