Burns talks about the “do one small thing” strategy in his books, and (anecdotally) it can be very effective. When you’re at a point where even the small step seems impossible, he has tips on drilling into the underlying emotions. Ultimately, your brain sees the discomfort associated with not working on something as outweighing the discomfort of actually doing it. Often, this is a cognitive distortion — which CBT aims to help one sort through. And sometimes the task really isn’t worth doing.
I know I go on a lot about meditation in my comments, but (again n=1) it can help clarify thoughts and emotions — particularly the kind of cognitive distortions that lead to self-destructive habits. Now I’m curious to learn more about ACT...