Psychiatrist Dr. Robert Weiss calls this "absorbing, sometimes maddening preoccupation that refuses to accept any conclusion" an "obsessive review." In my work with those wounded by adultery, separation, betrayal or some life trauma, I have often observed this "obsessing."
"Obsessing" or not being able to get what happened out of your mind doesn't mean you're crazy or abnormal. It's part of your process of healing. The "obsessing" process could help you get an accounting of the events that have occurred. It allows you to learn to accept it as part of your personal history.
However, although "obsessing" is a normal reaction to trauma and part of the recovery journey, there is a danger. You may become stuck in the "obsessing!" Getting stuck is not helpful and will keep you from moving on with your life.
In most cases, especially when therapeutic intervention is initiated, the obsessive thoughts and images return less and less frequently. In counseling, insights and techniques go together to address the concern. As you apply yourself in your personal recovery, the "obsessing" eventually ceases to be a problem.