You say in a comment that it's your house and that your ex loves the house, area, etc. Well, when you divorced that was one of the things that stopped being a couple thing and started being an individual thing. This is just part of being apart. My wife and my ex get along fine but there's no way we could be in the same house. I think its probably time to finish separating and be in a place where you can be fully with your current partner and put energy into helping the kids through this. But this is just opinion.