My Mom's on Medicare, type II Diabetes unable to care for herself and give her meds. How can I get help for her?

I have a 68 yr. brother that lives with her on medicaid and also has diabetes. He needs help as he is very sick and cannot take care of her. I work full-time and can only see her on weekends. She is not getting her medication as prescribed, no blood check, and eating things not good for her. She can barely walk as she can't seem to stay up and always in bed. She needs help and I don't know what to do. It's hard on me as well as I am 64 yrs. old with Arthritis in both hands and knees myself. I am running back and forth every week,making sure she has food to eat. There is a younger brother living there as well and he is living off my mother, eating the food I bring for her, stealing her money and I want him out. Can someone give me some Ideas and info that will help me out. Thanks. She is 86 yrs.old. She has a walker with bucket to use when she needs to urinate, but what she does is after wiping herself she folds the tissue and puts on dresser to use again. I am always telling her that this behavior is unacceptable, but she for some reason does not get it.