Stay away from negativity! Don't feel bad for doing it. If a person is mentally and physically draining, don't let them play the victim card and get you to stick around just to be abused. Get rid of that person.
We all are humans we make mistakes, small or major. A mistake is a mistake. We all made some or other mistakes but what do we do next? Do we criticize ourselves? Do we keep on repeating it? Or we learn something from it?