Sleep might be a necessary part of the processsing for you too. There are studies coming out lately about how people learn new skills better after they have slept after learning the new skill. When you're working on harder stuff you're likely to need to sleep more.

I also like writing down key points or insights from each session. I have a notebook for therapy and I write a summary after every session (sometimes I'm sitting in my car after session for up to an hour trying to get a handle on it). I also write down things I need to talk about next time, what I need to work on or think about in between, etc. And I keep that notebook with me so that if something comes up any time I can capture it, because I would forget if I didn't write it.