I know that anger ultimately is not the answer
Actually it is, or part of it. Anger is one of the five stages of grief, a stage that needs to be worked through on your way to the next one. The challenge with anger is channeling it in a way that serves you, and using it to be absolutely done with her strengthens your resolve, so that is a good use. By contrast, going out and getting drunk, getting in a bar fight and going to jail would be a response that doesn't serve you. It's not the emotion but how we use it, on the path to freedom. Take care of you!