At first your anger was a motivator for change and it was put to good use. I understand what you are asking now and that is to release yourself from anger and, I hope, also to find compassion for the alcoholic while also setting healthy boundaries and protecting your children in the process. Divorce is never easy, divorcing an alcoholic has it's own set of fears, unknowns, chaos, etc.
Others have given you good advice. For me, I had to go to a therapist/counselor and I attended Al Anon for a few years. The process led me to freedom from my own insanity. But, it's still a process and the anger is still there periodically. The good news is: I feel that I've developed tools for handling the anger and resentments now and that I know how to mentally and emotionally work through them. It was something that developed over time.
I started putting the focus on my son and making a consistent life for him. I took people up on invites to go to the movies, out for a cup of coffee, or out for a hike. I get a pedicure every so often and sometimes I treat myself to a new blouse or other indulgence. I make a concerted effort to improve my relationship with my Higher Power (whom I choose to call God).
You are a strong woman, you know what's right for your children and you will get through this. Sending you hugs and support today!