Sorry to read about your last conversation with H. I agree with StillLovesHim - H thinks it's OK b/c you're separated. Doesn't make it right, but in his mind it is OK so it's a good idea to try not to bring it up again. He's going to do what he wants anyway, whether you agree or not. Stinks, but it's true.
That's an interesting comment about you going away for a month or two... when you went away, did you contact H regularly or was that your break from the R for awhile?
I don't think you messed up by expressing yourself... if he's thinking about D he was already thinking about it, right? But that must have been painful to hear him talk about OW... as you know from my sitch, H hasn't said anything about his girlfriend and I can't imagine how hard that must have been to hear... Good for you for staying strong. Perfectly understandable that you told H how disrespected you feel by his choices. But if it's not going to help your sitch, maybe best to vent elsewhere and just show H that although you disagree with his choices, you're getting on with your life and it's going to be fabulous!