Anger--for better or worse?

I have long held my anger as a part of myself--something that defines me.  In recent times I have found it useful to put aside anger, allowing me a broader ability to accept the world with less clouded a view.  However, I feel like my resolve is crumbling without it.  Where is that inner drive to fight injustice in the world?  How do I protect that innocence inside me if I don't shell it in forceful resolve?  And YES it's worth protecting.  Everyone should have it.  

So how do you separate the "good anger" towards injustice and stupid things you put yourself through from the "bad anger" that threatens to grow into a consuming force of its own?