I'm not an expert on this subject at all, but it sounds to me as if maybe your clinician is threatened in someway because you are knowledgeable about this and want honest answers that she might not be able to give you.Intellectually it sounds like you have a good perspective on what is true disassociation and it would seem invalidating, if you are confident in what you know, yet open to further discussion. getting a second opinion might help.
warm thoughts