The only time you have to pay her is if she takes you to court and wins. Do not pay anything unless you get told to by a judge. Get a good lawyer who knows that the AOS is between you and the government not between you and her.
Keep all chats, messages and save them on your phone with screenshots. They can be deleted on the other end so get saving them now.
Get all the videos of that abuse to your lawyer. Also send everything nicely put no emotion in a letter to USCIS about that abuse along with restraining orders you should have filed before.