My Personal Opinion Only: The question for you is not whether you are wasting your therapist's time but whether you are wasting your time and money.

You have given this therapist and his approach(es) a good try, yes? Have you told him what you've told us here? Is he offering you only more of the same? Then it is time to consider moving on to something different. Yes, stopping and change are scary, particularly for us with MI issues.

Wishing you strength.