I have a lot of trouble talking too. Can you write (at home) and bring that in? My T has seen how hard it is for me to talk through things, and is OK with me writing out things and bringing them in. I used to give them to him at the end of the session, but he's been encouraging me to give them to him at the start, so we can try talking about them - even if I can't say much, he reads it, and is able to respond to things and ask questions... so I get some kind of response.

Not perfect, but it's a way to get started, maybe?