I think this is really important to tell him, even if it means printing out this paragraph on a sheet of paper and handing it to him. Ts like to know how they can make your therapy go better and help you. This sounds like a really clear and concrete way your T can help you in therapy. I am not a fast processor and frequently don't know what I thought or felt until after the session. I have gotten better at this through therapy, though. My T is pretty good about giving me space to look inside and get a glimpse of what I am feeling. I also never say "I don't know" to my T. I at least try to look inside and give him a flicker of a thought or feeling. I am also not afraid to sit there and think for a bit in silence when he asks me a question. And he knows enough not to interrupt. My T has a big personality and is an extrovert. But somehow in session he can tone that down and allow a more introverted person like myself the time and space to think, feel, and speak. I hope you will share what you wrote with your T. I think it will really help him know how to better interact with you. Good luck!