Have you and W ever talked about visitation with the kids? (Not that you've talked about anything...). Having to go to her place to hang out with them doesn't make any sense. You should have scheduled time with them AWAY from the house. I know your current place is small, but you don't have to be there, though it would probably be fine briefly.
I know this stuff will come up in the D settlement, but I don't think you need to wait for it, do you? That way you'd have your time with the kids, W would have her space, and you wouldn't have to hang out there feeling like an outsider and having to deal with W.
I don't know if it has to be crazy-making all the way through. I'm just thinking if you can see your kids and avoid dealing with W and being in the house at the same time, it might help you stay centered.
