Hi Elevated,
It sounds like you may have found a good t. She noticed your dissociation right away. And she is teaching you grounding techniques right away. Both of those seem like good signs to me. If she is that familiar with dissociation, I think she will probably be able to tell, after a while, if you have DID. But in the meantime, it sounds like she will teach you some skills to lessen the dissociation. Dissociating can be very disturbing; I am not surprised that you are feeling so out of it.
You said that after the grounding exercise you just feel sort of "so what". I think that may be a sign that the grounding is working.