Hi ame- Welcome to the boards, although i am sorry that you find yourself needing to be here. But, you came to the right place. When i read your first post, there were a lot of similarities to my sitch, but i won't bore you with them.
RE: you going out tonight with your H - you have to act as if you are happy. Have a good time. Don't talk about the R. This is an opportunity for you to remind your H of the good times b/w you two and show him what he might be missing. No R talk is a rule to live by. Go, have a good time. Give yourself a break from thinking about it.