Hi Lynn P - I can somewhat relate to what you are saying. My ex still lives with me in my house with our kids - I have asked him to leave a couple of times, but he just doesn't - he is so dominating and I am so passive, I can't get him to do what I want. I am starting to become less tolerant of the situation and generally have my head screaming at me pretty continuously - "I just want him out of my f'ing house".
However I have to say that at some level it does work, particularly in that the kids see both of us everyday and do not have to deal with having 2 different homes to live in.
So I hear how difficult your situation is, but it seems that you think it would not improve things for you if you did leave and may actually make things worse?
I just try to grab what space I can to try to chill a bit and hope that in time the awfulness of him being here still will out weigh the negatives of him leaving. Take care of you -