I know you’re hurting right now, but he needs to be called out on this. That reply was NOT good enough. How can a mental health professional not understand an eating disorder for a year-and-a-half? You mentioned b/p cycles. That’s not the behavior of a non-eating disordered person. And honestly, I would flat out ask him, “are you actually giving me the green light to suffer in silence?”
Bottom line — you’re the patient - he’s the professional and should act like it.