Kimmy,
That is stressful! While I agree, it is better to be 'happy', I would offer the suggestion of looking longer range. I would branch out, take on anything new, in the different department. Why? You might become more experienced, more valuable, and keep a job. It sounds like the boss you have now would make an effort to find something for you to do, if it didn't work out in the new 'job'. I would keep that as a fall back position. I have rarely found being 'resistant' in the workplace to be of use. I am not saying you are being resistant in the typical sense..but, more in the 'gotta stay floating along like the rest of the people". The saying, "everyone is replacable" is a little too hard to get over.
Good luck with whatever you do.