1st off, you did it. Feel your strength!
2nd, I understand. Mine is the same way. We are not as far along in the process as you are, but my ex is a narc and blames me for everything too. I’m terrified to be in the same room and have him dominate the conversation and win them over. He will paint himself as the victim, talk over me, and then I get flustered and lose my train of thought. I have to write notes sometimes so I remember to say certain things. It’s so hard! I am so sorry you are going through this. You’re doing great. I am so happy you have support and they see right through him.