Anger is a natural stage of the grieving process. Please don't beat yourself up for being angry. If you didn't get angry, you could never work through those feelings and they would cause bigger problems later on.
The way I chose to deal with my anger was to journal. That way, I could rant and rave and curse as much as I needed to without hurting someone or regretting my own words later on. It was my own private place to get out whatever emotions were needing to come out. And, amazingly, the anger transformed from anger at him, to anger at me, to forgiveness of both of us. There is no shortcut, however. Emotions need to be felt and worked through if you want to get past them.
It's okay to be angry. And it's okay to forgive yourself for being angry.
L