I've been through this and we've survived two Christmases since; this will be our third since it happened. Some of what you say worries me though. It doesn't sound as though your H understands your loss and grief. You don't say how you've been getting through this, apart from counselling and it doesn't sound as though he likes talking about it outside of the therapy room. That counselling will be greatly diminished if you are not talking about this in between times.
The other bits that worry me are your statements about gender differences "like only women do" and "like most women". I think gender politics play a huge role in affairs and so I'm curious about these statements.
Lastly, I hope you didn't mean what you said and that you are staying together for the DCs. I hope you are staying together because you love eachother and don't want to be apart.
Christmas can be a hugely emotional time but it all seems more so, after a betrayal. I expect you are comparing this with Christmases past before disaster struck, but if you get to the bottom of why this infidelity happened and take a more holistic approach, it really does get easier and in fact you can get to a stage where your future Christmases are better than they ever were.
If it helps at all too, the first Christmas for me was easier than I'd imagined, because it still felt as though we were in crisis mode (only 3 months on from discovery). Last Christmas was worse, because the crisis has passed and despite us having done a tremendous amount of work, I was feeling very sad and tearful, but this Christmas and for several months now, I have been feeling wonderful and "normal" again.
These things take time and I have learned that you just can't rush through the various stages of recovery. Lower your expectations about Christmas and raise your expectations of your H and the necessity to talk when you need to and to really get to the bottom of why this happened.