I haven't had quite the same problem. I suspect maybe that's because I've found most of the sessions sort of equally challenging to believe. Not impossible but challenging. The big difference I noticed with Session 5 (which I've just started on this week) is that there's just MORE to do and read this week.
I can relate to the idea of "believing the idea on paper" but really at a deep level in my mind. I think this is where the daily repetition comes in though. I've found that by reading the handouts for a week each and every day, that they really do start to seep in better over time. So I'd just say to stick with it --and I reckon that some ideas will be harder to accept/believe than others, and those are just the ones where we'll have to keep reading the relevant handouts for longer. That's the way it's been for me thus far -- with some handouts I could just tell that I wasn't getting anymore out of it (these tended to be ones with ideas/messages that I accepted and believed quite readily) so I only read them for 2 or 3 days, while others I keep going back to even after a couple of weeks.
Regarding your expressive face, I can't say that I think that's one of my particular problems (though you'll probably have me worrying about that one now too! ). I would just say with a fair degree of confidence that: 1) I'm sure t's not nearly as bad as you imagine it to be and other people probably don't notice much if at all; 2) Even if they do -- "Who Cares?"; 3) I'm sure this series will help with this issue, because it's clearly related to your social anxiety, which will eventually get better as you move through the course (we all need to believe that, right? )
I think the important thing for us all to remember in these early weeks is that we're mostly working on changing our thinking and that the behavioral work comes later. So yeah, I'd just try to keep reading the handouts as much as it takes and try not to get ahead of yourself in terms of thinking too much about how it will all be applied in the weeks and months ahead.
Hope that's somewhat/somehow helpful.