I can understand why, especially after 18 years, a T would feel a deep attachment to a client. Knowing how the limbic response works it seems rather impossible that there isn't at least some attachment on their part anyway. That being said it still makes no sense why she will not disclose to you why she is against your terminating therapy with her. I understand this would be very difficult for her and that she would hate to see you leave her, but knowing that you are continuing your therapy with a more well suited T should give her a sense that you are ok. (I get the idea that is your plan anyway) If it is about her attachment to you then I would hope she would seek supervision to deal with her feelings and allow you to move on if that is what you feel is best. If she has allowed her attachment to cloud her judgment that could be why you are no longer progressing.
I am so sorry for what is going on and I don't think I can even imagine the depth of it. However you were re-traumatized it must be playing a huge role in what you are going through (I know that is the understatement of the century) and perhaps you need a fresh perspective. It is nothng against your T of 18 years, and who says there has to be a complete break; unless you want it that way?
What seems very significant to me is that your T has been allowing you to leave her office in such a dissociated state. I agree you _need_ more grounding before you leave. So I ask, have you made this known to her? How well do you feel you are communicating to her? I have left session before and not been grounded. My T has admitted not realizing how bad I was at times and I'd find myself at home curled on the floor or in bed for several hours. I am a master at disguising my needs. But I think she is onto me now and has learned to spend several minutes at the end of session grounding me and not just trusting me to sit in the waiting room or in my car on my own. Once I start walking out the door I keep walking, driving, and then next thing I know I am home. But I think I finally communicated that to her enough and she undestands my needs a little better.
I hear you about the touch on the shoulder or arm and I never quite understand a "no touch policy." Perhaps in some cases that is necessary, but to me it all goes back to understanding the attachment process and secure and insecure attachment. W/o any touch how can one form a secure base? Sometimes all it takes is a little touch, a handshake, and even a look. When I used to dissociate a lot more in session, my T used to tilt her head a certain way and look "into me" and somehow she would reach me. I love that.
I am sure that you must be afraid that this shift is permanent.I know I have been feeling that way myself the past several months too. But I am certain that if it was managed before it can be managed again. If your T is not the one for the job, then so be it. However, I don't think that has to mark the end of the relationship entirely. Perhaps you could still see her on occaision and be able to call or email her here and there. I am sure she would want to know how you are doing. And as for the termination process, I would think that it should take as long as you need it to take and helping you to transition from one T to another. Saying good-bye can feel very traumatic and it needs to be done carefully.
I don't know if any of this is any help. I don't know how insightful and of this really is, but I reallyhope you are finding the support you need here. We may not have all the answers but we do care.
JM