Its tough to do. Ive sat there for a lot of long silences trying to say whats on my mind. Sometimes it works, other times I write it and send it later. Sometimes it helps to just say one word related to the topic and my T will try to help ask questions to fill in the rest. Like if its a topic we talked about recently or a feeling. Maybe ask him if he could bring it up more often. Check in with you on how the thoughts are.