Why don't you just tell him what you wrote here, that you have something to discuss with him on Friday, and you want to do it in session, but you need some reassurance from him until then. In a sense, our Ts are our security blanket, I think, and there's nothing wrong with that, in my opinion. He won't think less of you for wanting to touch base with him, especially when he has told you to in situations like you are in.

Tell him you're panicking, but you still want to wait until your session to talk about it. Any chance of scheduling it sooner this time? In order words, my advice is to be totally honest with him, even if it's to say "I don't know exactly what I need from you, but I need something."