(((safe hug)) No, not a disaster at all
What a kewl T that he had paper and pencils to draw and color with!
IMO T will not offer information that you might be keeping separate from "yourself." You have to be the one to acknowledge that you realize you might have another "personality" "alter" "part" or whatever you are choosing to call this aspect of yourself.
I think it's important to fill the T in on all you might know about this part of yourself. If you don't have anything at all concrete, but only glimpses and suspicions, then if you can share that with him also, that will help him help you better.
Even with the acknowledgement, I doubt T will share with you what goes on when you are not "there" but the other is. You have walled this part of you off for a reason, and T isn't about to just tear that wall down at this point. The other may have information that you really don't wish to hear right now, you know?
Don't feel afraid. It sounds to me like T has things controlled and is confident in his ability to help you.
TC