This, this, this. You can't let go if you don't know what exactly you are trying to let go of. I'm working on my anger as well. I remember reading somewhere once that anger is always about another emotion. For me, a lot of it seems to be about fear. When I can figure out what's really going on, it immediately takes the anger and the fear down a notch so I can think more rationally. But like you alluded to, it is taking lots of practice (and patience) to retrain my brain to respond in a different way.