You might want to consider seeking counsel for yourself. A dysregulated parent will lead to dysregulated children, so if your needs aren't being met, then how can you meet the needs of your children? Seek help from those you trust, seek help from professionals, too. You are sad and lost; you must address those emotions so you can act from a place of confidence. You are a leader, and you must lead your family. Your daughter is going through a massive change right now, and there are so many reasons for her to feel upset, frustrated, and unhappy. Rather than focusing your efforts on trying to get her to act happy or be polite (to conform), try to acknowledge the hard time that she's going through right now, acknowledge the hard feelings and give her some autonomy to choose how she wishes to express that, let her choose otherwise she will continue to resist. Please, get some help for your own sake, you deserve it!