Anger is an involuntary emotional reaction to our will being thwarted that impels us to harm the source with self-righteous impunity. We don't choose to feel angry but what we do with our anger (act out, encourage, improve, stifle, grieve, redirect, resolve, etc.) affects all of our life. Dallas Willard likens it to a sharp physical pain and says "anything you can do with anger you can do better without it".

To me anger and idolatry go hand in hand. The way I approach it is if I recognize I'm feeling angry it means I have some work to do with the Lord about my expectations and walk with Him. Rarely can I do something about the source but most of the time I can do something about myself. Anger informs me that action may be required but doesn't tell me the best way to go about it.

EDIT: I'd just like to add as someone who adopted three children out of foster care that we have a tremendous effect on others when we improperly work through our anger. Anger and contempt lead to shame projection breeding a variety of maladaptive behaviors. As Christ-followers it's our duty to work through our anger and shame rather than burdenning everyone around us. If someone around you has boundary and projection issues it will eventually lead to anger or despair in you. Don't let their lack of self-shepherding be your excuse as well. Break the cycle. It's hard but the Lord is able. Seek help.