I think it is okay to be compassionate with your self and all your parts about what erupted in session yesterday after the trauma. In the circumstances it was what it was and you did the best you could at the time. In those particular circumstances the variation of human response based on unique human experience is an unknown quantity. it wasn't predictable or foreseeable, but more like "hang on to your seat fellas, and hope for the best!"
Maybe it is also okay to be compassionate with your t about him not reacting in the best way to the traumatic responses unfolding in the room before him. He too was likely hanging on to his seat and hoping for the best as he tried to respond the changes in you. (A good T for dissociative disorders doesn't have to know everything, just be really open to learning.)
Its good you are able to continue processing and see T again tomorrow. I wouldn't make any hasty decisions based on how your last session unfolded. Hopefully you will be feeling more grounded tomorrow.

I had a similarly bad session yesterday. I went to see t immediately after something traumatic, and knowing that more trauma would follow after the session. I was unable to communicate with t and we entered an even deeper traumatic state in session when stuff that triggers into an "about to be abused space" was happening around the therapy room. T was unable to help in any way at all. We just wanted to leave so we could feel at least a little less traumatized.
But yesterday was an anomaly. The trauma before, the trauma during, the trauma that was going to happen after. It was a one off (I hope!) session. Parts don't want to return at this stage but we just have to wait until the internal reactions settle down and take another look at it then.

Good luck tomorrow. I hope you are able to feel calmer, more stable, more in control.