If she refuses to try, and you are miserable, then you have a very tough decision to make. If you do decide to separate, though, you should definitely find a good therapist to support you and offer guidance, because it will probably get extremely ugly. She will likely try to turn your kids against you and make you out to be a bad guy who is mean to her and who doesn't really love them and so on. That could be an extremely painful, enraging and all around crazy-making thing for you to go through and cope with. So whatever you decide, make sure you line up proper support for yourself.