It sounds like the psychiatrist might have forgotten what he said to you about the book? Sometimes specialist doctors are extremely busy. Sometimes my own therapist is so busy that she'll forget she said something to me, and after more than four years, it can still hurt at times. And my psychiatrist forgets a lot and contradicts himself often. Otherwise your psychiatrist still may have just expected you to go off and work through it one chapter at a time on your own, and then bring up how it's going each you see him (when you and he would work through it together, since that's what his original suggestion sounded like).

When life is really, really hard, it's so easy to take those sorts of events as a sign of something about ourselves and who we are to other people (that we're not worth remembering or following through with etc). As I've improved in the course of my own treatment, I've realised that I have to take equal responsibility for certain things. It's absolutely not what I would have managed or even considered to be fair earlier in my treatment, but in hindsight, it's something that I've worked towards.

If my therapist forgets that she promised we'd work on something together, I can (now) choose how I react. I can remind her, hey what about that thing you said we would do together? I liked that idea and I made a big effort so that we could do that. I do find that it is so much more helpful to have someone help me and keep me on the right track. So I do hope you have someone to help you work through the book, particularly because of the effort you're clearly willing to put in.