Showing you are trying to overcome these feelings relating to this women and what your ex did to you. When someone cheats on us, it leaves very hard emotions that can take a long time to work through. Since you beat her up, it is showing you are trying to overcome these feelings, but since you ran down a staircase you are running away from the situation or the emotions relating to what happened. With your friend who turned the light on is trying to help you in this situation. You will have to overcome your feelings of fear and overcome what your ex did to you so that you can move on in your life. I would continue to seek guidance and help from this friend that was in your dream.