"I still listen to him and get upset about how foolish and childish he is. His lies and lackadaisical attitude enrage me and I can say mean and hurtful things."
I think you're still working on detaching. You may know that the relationship is at its end but you still think of him as yours. The more you separate your emotions from him, the less these things will matter. Would you become "enraged" if my husband, whom you don't know, was lackadaisical? Nope. This is still bothering you because you still have feelings about him, even if they aren't feelings of affection. Keep working on detaching your feelings from him, I think.