Wonka is right, Peter. The problem with "grand pronouncements" about "moving on" is that the very pronouncement itself indicates that you're NOT moving on. It comes across like you're trying to get some sort of reaction out of her, and trying to get her to stay.
I think it would be much better, considering just HOW far along you are in your sitch -- and considering you totally lived up to your end of the bargain in waiting for after your stepdaughter's wedding -- to merely just let her know you've got a place, and you're moving out on the 30th (or whatever). At MOST just say "I have decided that this isn't working for me anymore, and I need to get on with my life."
