You can leave school thinking about a student who had a hard day and still be glad to head home. Maybe you make a note to check in with them tomorrow. If something needs immediate attention, you involve the appropriate people before leaving. Then you go home, even if there are emails unanswered or lessons you could keep working on. Caring about students doesn't require treating every unfinished task as an evening assignment. Teachers need time to be people outside their classrooms, too.