I don't think the friendly exchanges are a bad thing. Like talking to a work colleague about a joint project. Sometimes there is small talk, sometimes it is straight down to the work stuff. It does seem very fake. We are both very careful not to say anything that will lead to R talks.
I read some of the threads on here and think, it would be so much easier to detach if my H was just a straight up b****d. At least hate could drive me forward. At the moment I am just stuck.
I have taken a few holidays on my own since BD. I did a weeks yoga retreat and a three day spiritual retreat. I found these really useful. I came back lighter after both. I would definitely recommend it. Though, it didn't take long for the weight of reality to hit me.
If it helps - the sadness occurs less now. I cried practically every day for months. Songs, movies, looking at my ids, anytime someone mentioned his name. Though, when the sadness hits, it is as intense as when it first happened.