Your emotions are simply signals that your body is sending you. Anger is a signal that a rule you feel strongly about has been violated. At its core it is a good signal as it is mean to propel you to action. You should never feel dumb or idiotic for having convictions. Once you start to observe your emotions rather than blindly reacting to it you can take tangible action.
As I see it. As long as you cannot properly defend your faith then you will always become angry. Read and study more and become more comfortable in your understanding of Faith and God, then when you are in a situation that makes you angry you can react in a smarter way than simply feeling like breaking something.
Not a complete solution, but hey we gotta start somewhere right?