I tend to feel that most people that really want to leave a group just leave without any fanfare or notice. Those that have to post a long and bitter "farewell" are often looking to be talked out of it.
So I'll say it. Billhaven, I wish you would stay. However, if you're going to go, you have your reasons, and sometimes it IS healthy to step away, at least for a while. Perhaps you'll come back when you feel you can?