Let's be honest. "Do what you love" is great if you can swing it, but nearly everyone will have to get a job they hate at some point. If you don't want to stay there, though, treat the job like it's just training for a better one.
Photo by mjtmail (tiggy).
As personal finance blog Dividend Mantra points out, having a job you hate can go one of two ways: either it can slowly suck you in to stagnation, or it can motivate you to try for something better. One of the key ways to avoid the former is to treat the job you have as though it's training. If you're using that job to learn useful skills you can apply elsewhere (perhaps while looking for alternatives), you may be less likely to slip into the mindset of just accepting that job:
If you have a job you hate, use that to your advantage. Use it to fuel your fire… But don't sit in boiling water for too long. Don't wait until the chains are too heavy to break to give them a good tug. You have the power to be free, and perhaps even faster than you might think. Make sure you're taking advantage of that every single day.
The key advantage to this mindset is that if you're planning to move on to something better, you can spend your time learning skills that will be useful elsewhere. This is also something you can do even if you can't afford to quit your job.
While it's nice to think that everyone can just quit and find a better job, you have to pay the bills. However, planning to leave some day and using the time in between to learn new skills can never hurt.