One, it's not rude. Most people who are there are having a difficult time. When you are in a bad place it is hard to think of positive thoughts. I have started journal writing. On days when it's bad I simply state what I did for the day. So I don't force myself to have happy thoughts but I also don't concentrate on the negative ones either. Automatic thoughts have a way of twisting facts.

Secondly, I would not ignore what you blurted out. You may have slipped in saying that to him, but if you find yourself asking this, maybe this therapy is not working for you. I would look into another form of therapy. Maybe the cbt therapist can give some advice or maybe he can give you some advice on how to make this therapy work. Has he provided an example for you, on how he thinks you should accomplish this task?