The past is the past and you cannot change it. But you can control your attitude about running now. Run for you and run for your future health and well being. Listen to music, work out probelms in your head, enjoy the great outdoors, and get buzzed with the knowledge that you are taking charge of your physical and mental health. It does not matter if you run slow or if you have to repeat a week. You are still faster and farther ahead than the person sitting on the couch. And at the end of the day, the only person you have to satisfy is yourself.