I would clarify the "end" of what; could just be the end of the six months meaning that the review is coming up, etc.

Do say "something" to him about how much you are getting from seeing him! Therapists don't really have any other measure besides what we say/do. If you want therapy you have to at least say that, as risky as it is, or the other people don't know. It may not continue but it would truly be sad if it ended only because you didn't "understand" what he was talking about and didn't take part in the review, etc. It is impossible to be "bad" at therapy since it is your therapy.