The truth is that she became your ex for a reason. There may always be the nagging fear and memory of her leaving, and the possibility of her leaving again. Sometimes people get stuck in one and do not move through to the other side. Denial can suggest to you that she will be coming back - so you never completely grieve or move through the fact that your marriage has ended. That places a hold on you getting on with your life as a single person and parent.
Anger is actually a healthy emotion - it is appropriate and normal in divorce.
Like denial, bargaining comes in waves. Next can come depression, which is a state, in which you feel your life has ended. You are bombarded with negative thoughts and painful projections. Here, it is best to acknowledge those feelings without acting them out in harmful ways. Speak to a friend or counselor when faced with depressing feelings and thoughts.