As I am unsure of your ability, I cannot really say what you personally can and can't do, however I will attempt to give you general ideas of it.
First, you can look for another job. Yes, it's not easy to find a job in this economy blah blah, but if you are really wanting out of the situation, you can leave and find something comparable. This hinges on your ability to wait it out and keep your mouth shut about your boss and wanting to leave.
Second, you can stop worrying about your boss being impossible and live with it. Sometimes the best response is to just shrug and go with the flow. Unless they are doing something illegal or unfair, I would take this route first.
Third, if it is something illegal or unfair, you should contact your boss's boss or your human resources manager. If you do not have either of these, you will want to look into a general human resources manager or into a lawyer. You need to protect yourself from people who would abuse your position and you.
If you really wish to do a spell to rid yourself of your boss, you should do something simple, such as a spell using candles and a piece of paper, writing your wish (for your boss to not be around anymore) on the paper and burning it with the use of the candle. If you take this or any other magical route, be sure that you are specific, as "I want rid of my boss" means anything from a promotion, a firing, or death. Words and intentions are important in magical practice, and as a practitioner you would do well to take note of this.
I agree with the posts about trying to suck it up or quit, but barring that, I would suggest using love. Thats right, love.Try to bless him or her with a promotion, or to become more personable. Maybe he or she has problems you have no idea about influencing them. Work positive love to the person, to help, and reap the return.
if I where to use a spell I would do something like, make her see, let her know how it feel to be you in that situation and how your boss can communicate better or you could cast a spell on your self so that you work better with you boss.