I may have more bad news for you, and I know you've had enough. If the money he has appropriated is considered a gift, the gift tax is owed by the giver.
It may not be worth much, but my state has an agency called Adult Protective Service. New York probably has something similar. They are involved in physical and emotional abuse, as well as exploitation. Around here, they are pretty toothless, but anything is worth a try.
Once again, you need your own lawyer. As Joe has pointed out, your mother's lawyer has no obligation to you, and probably couldn't help if he wanted to.