Hi, I'd like to help you with your question.
It sounds like your partner has a lot of unresolved issues from his past. He is bringing those issues, including those with his mother, into your relationship with him. He needs to resolve this issues in order to be able to have a stable relationship.
You have two options here. You can stay with him but insist on counseling. In counseling, you both can sort out these problems and work on how to communicate better. Your partner can also see how his past is affecting his relationship with you. If he refuses to go, go yourself. You can use the support to help you decide what to do.
Your other option is to leave. This is a hard decision because it not only affects you, but your child as well. But given that he is being abusive, leaving is a good option. You do not want your child exposed to his behavior. It is natural that you still care enough that you don't want to leave him without the ability to help himself, but he is an adult and he will need to be responsible for his own needs. You cannot stay in a bad relationship just so you can take care of him. If you base your leaving on that criteria, you may not get out of the relationship at all.
I hope this helps you,Kate
I understand. It sounds like you need to consult an attorney to see what evidence you need to be gathering for your custody case. You both are at odds with each other and gearing up for a custody fight. It does sound like the relationship is over.
Also, consider getting your daughter into treatment so whatever happens she is not affected as badly. Ask your attorney if you should have an evaluation as well to prove that you are mental fit to care for your child.