That's a difficult one. I have been battling that one for a while too. In my case, my W sent me a long depressing email about a month ago that gave me a reason to tell her that it seemd she was really donw and that I wanted to help her. And I proposed that we go see a counselor. She agreed. That's the only idea I have...
A vacation w/o H's, sounds like a good thing for you actually! You can concentrate on the kids and just have a good time with your BFF... Keeps your mind off of things!