Look on behavior change as a process composed of many steps. You may have success in dealing with some components of the problem only to find later that you are resistant to making more changes. Then, in therapy, you look into your resistance to see why moving on is difficult at a particular stage. And don't forget that most people relapse. Research has found that only about 20 percent of all people make complete changes on their first try.
Most people have setbacks during the change process.
To relapse does not mean that you have to start all over again. You can change uncomfortable patterns of behavior, and procrastination, fortunately, is one of those habits most amenable to change. Break the Procrastination Habit, by William J. Knaus. The Six Styles of Procrastination and How to Overcome Them, by Linda Sapadin and Jack Maguire. A Strategic Program for Overcoming Procrastination and Enjoying Guilt-Free Play, by Neil A. Fiore.