Who knows whats going on in his life right now! I agree it's best to go to the next sessions and talk it through. Do you think he needs to know that you trust him and you want to stay with him? Maybe he's feeling a little insecure/unsure of himself as you're his first CSA survivor. I'm not really sure how much one should support one's therapist, but they are only human.

You don't want to be hiding emotions etc from him, that's not what therapy's about and I don't think you should blame any of this on yourself.