Been there, done that.
As I was dealing with my AH I experienced a huge amount of anger. When it started seeping into other parts of my life - and I was taking it out on other people - I realized that I had a problem. I needed to start dealing with my anger.
Ok, knowing this is the easy part. Dealing with it was difficult. For me, I realized I was angry when reality and my expectations didn't match up. There comes a time when I had to quit expecting my AH (and RAH) to act like the person I wanted him to be. I realized that I was looking for my AH to validate me by taking my feelings into consideration. When he didn't, I was offended and angry, and walked around with an open wound. That meant the smallest slight by someone else set me off. My reaction was disproportionate.
As I began to accept that I might not be treated as I want to be, and that this was not a reflection on my worth, the anger was replaced by sadness. There were days when I missed the anger because it created energy, whereas the sadness took energy from me. But for me it has all been the process of becoming better grounded in reality. I had to experience a sense of loss to move on emotionally.
I also found that I needed to forgive my RAH. This has been difficult, and I'm working on it. I have started a list of everything which has made me angry. I am working to release this anger - for me, not for him. I need to get past it and have a more positive life. I am getting there but it does not happen overnight.
Good luck.