I was under the impression that both of you had not seen a C together. If he didn't want to go to C before, I wouldn't bring it up now. He has to be ready for it. If not, you are going to bear the brunt for all the "problems" in the marriage which you know isn't true.
Again, stop thinking that you blew it. If you did, he wouldn't be coming back even for the dog. Read some of the other sitches on here, you'll see what it's like when the spouse doesn't come back at all.
Honestly I stand by my statement of what to do when you see him. He has to feel you pulling away and that he is losing you, perhaps forever.
You need to get rid of the fear first and foremost. Before you see him, do something physical, like running to get rid of the anxiety. You have to be relaxed and confident. There was a poster named Lost Rabbit on here who did exactly what I had suggested above and it worked. Her sitch and yours are very similar in that the WAS kept in contact with each other. At the very least, try it this once.
M-43 W-40 2D - 9 and 5
Emotion, yet peace. Ignorance, yet knowledge. Passion, yet serenity. Chaos, yet harmony. Death, yet a new life.