It sounds like she is really having a hard time. I hope your therapist can help you with the emotions around the situation. It sound like she is unstable with her emotions and what she wants. It also seems that she is pitting you and your ex against eachother to get what she wants. It may be hard, but getting on the same page with your ex may help you and her with some stability. Accountability is hard, and as a young girl, I think its really hard at that age especially because its when people graduate college and become adults in the real world. She has to learn how to manage her life on her own (which will be hard but give her confidence) while getting support from both parents. I think it makes it hard for her to have 2 different people give her different rules while also figuring out itself. Also she may get even more angry at you but you have to remember violence is never ok, whether it's a husband beating his wife or a daughter throwing stuff. Please keep yourself safe. You never know how if it will escalate if you let it keep on happening.