My W has also had anger issues for much of our marriage and is now in a depressed state. I'm still trying to get a handle on things and I make mistakes daily.
One thing I can say, with the niceness and anger she expresses to you right now is to not over think it. You obviously will, but try not to. It will drive you crazy and cause you to develop expectations as a result of the nice behavior. Just try to keep doing what your doing without reacting too much to whats shes doing or saying in the heat of the moment.
Accept what is, let go of what was, and have faith in what will be
