Yes, this happens to me A LOT. I shut down my emotions - not consciously, it just happens. A few times I've gone in completely numb. I hate it - I need to bring those feelings into session.

One thing that's helping is to write down what I'm feeling and take it to the session. Sometimes I chicken out, but I have been able to force myself to bring things up even if I'm not feeling much. Much to my relief, I've found that often the feelings will come back when I talk about it in session.

I think the feelings we have after sessions are important, and I hate to feel them going away, as I rationalize them away, or block them, or whatever. Maybe try writing them down and bringing them up anyway, whether you're currently feeling them or not? This is the only thing that's helped for me. Maybe others will have some ideas.