What are my options on this whole mess?

My Dad passed 2 years ago and my Mom has been rapidly declining. My 2 half brothers have been having fun getting money from her and I know Mom has no idea what she even has. She has memory problems , I am sure she has no idea the consequences of her decisions. She co-signed for one of my half brothers who is 48 years old s he started drinking after my Dad's passing and has managed to ruin his 17 year marriage and can not see his twins who are 6 years old. I went for POA with my Mom in December 2012. My brother is livid and came over to Mom's house and beat me up in front of her and pulled her phone out of the wall. I went to the hospital and he went to jail for the weekend. I took Mom after that to FLorida for 4 months, the stress was no good for her. Adult Protective services were notified and called repeatedly and said they could do nothing as Mom authorized all that she gave out. Her grandson stole over $20,000.I had him kicked out by a restraining order. So I have been through hell,, My Mom's elder lawyer says the only answer is a guardian. However, these are very expensive and most of Mom's assets are now in her home and the land. My brother not making his house payments could make Mom liable and have nothing. Medicaid goes back 5 years and seeing she gave money they will not help her. I am so upset. She is in Assisted Living as of 3 months ago and it is $55,000 per year. My pathetic brother is staying up there constantly and eating which costs money and I called the place and said I would not pay for his meals and he could be dangerous as he is still drinking. They said they can not get into family affairs. What on earth am I suppose to do???? The icing on the cake is I brought Mom for a 3 day visit at my house and there was a bad snow storm but she needed to get back to Assisted Living as she is a diabetic and has heart issues and we had no more medication. My brother has all wheel drive so he was going to take her, he needed gas money because he is a bum. I had no cash so I gave him Mom's debit card and he dropped her off filled his tank for $50 and proceeded on a $1,000 shopping spree!!!!!!! I call Mom's lawyer and again he said you need a guardian. I called APS and nothing,,If I call the police he may kill me , he is on disability for mental issues and has not been taking his medication and is the one who started drinking,,, Can someone please tell me what I should do?? I am at my wits end and very depressed:(