Just wondering if you have personally contacted all the therapists in your area to ask about dissociation. Often they don't advertise it. The T I see now has quite a lot of experience with DID but doesn't advertise that on her website. I had considered her when initially searching for a therapist but discounted her because she didn't even talk about working with trauma clients. But my ex-T referred me to her when ex T left her practise as she is experienced and trained in treating DID clients, she just doesn't advertise it.
Just a long way of saying if you haven't already called and personally asked each T about their experience with dissociative disorders it might be worth a shot.