You say you have grown apart? Can you figure that out and get back closer together? I would not stay if I were that unhappy and couldn't work it out; like henrydavidtherobot says, you do not have to be together to parent together. If you were to find someone else you were happier and healthier with, that too would be good for the children when they were with you; the example you are setting now, is that how you want them to view life?