I feel like I'm not honoring my mother in her best interest now that my brother has all the control. Now what?

I was caregiver and financial manager for my elderly mother for approximately 5 years until my brother took her to live with him a few months ago. I could not accept the manner or reasoning behind his decision. He had another agenda and whether I accepted or not, he would proceed as he wishes. I refuse anymore conversations with him for that reason, and he's livid and so angry. I refuse to turn over mom's bank accounts and personal property at this time. He's since reported me, turned my mother on me, closed her bank accounts and opened new ones with his name listed as sole beneficiary. Mother in her right mind would not do that, but she is so brainwashed, she'll sign whatever he tells he to. In the meantime, I'm stuck in an uncomfortable position I didn't ask to be in. I feel like I am not honoring my mother in her best interest, and that he has all the control. He sends demanding letters. I have seen a lawyer, but I felt worse after that consultation. My brother's been a deadbeat son for years. It sounds like he is now in charge of all of her decisions, yet there's nothing in writing legally proving he is so superior all of a sudden. He forbids me from seeing my mother, If I try to she will tell me to get away from her. My brother will get mad at her if she has anything to do with me.. Maybe someone could shine some light on what's going on and what to do with her remaining money, That would be nice.