I don't really know what to think of anger. I do think that anger can be appropriate and useful. I think people are too often shamed for being angry. It's probably the most maligned of the emotions (maybe along with jealousy). I'd agree that sometimes anger can become an obsession, but I also think that, because of societal pressures, we're often not allowed to deal with our dark side in ways that could be beneficial.
I think one of the things that drew me toward Jordan Peterson's lectures is that he address the inner "monster" and acknowledges that we all have the capacity for evil in its most violent and repugnant manifestations. He also talks a lot about the Jungian "shadow." What I like about Peterson's approach is that he doesn't shame people for having a dark side. He pushes you to accept it and understand it rather than immediately dismissing it. Just knowing that it can be okay to be angry and have evil thoughts can be a great relief.
Peterson, and others, also talk about integrating the monster or the shadow. At first, I didn't understand what he meant, but now I think I understand integration a little better. When you integrate your anger, you can still access it when you need it. I think that was one of my biggest issues; if I were to lose my anger, then I'd be open to being a doormat again. By acknowledging that it's a part of me that I can use at appropriate times, I no longer have to worry about losing that part of myself, and in turn, I don't feel like I have to stoke the fires of my anger to keep it burning because I'm confident I won't be a doormat. And I think that's the key.
