I am at the end of my rope taking care of my unruly grandmother. I need another option that isn't a nursing home.

My grandmother is completely unruly. In her younger years, she was abusive, and violent. The object of her aggression was always my mother, but since then, they had buried the hatchet...or so we thought.
2 years ago, my grandmother had broken her hip and gotten C-DIF. My mother helped her, got her therapy, cooked for her, cleaned for her, until she got better. Problem is that she still isn't better. We have taken her to Doctors, Neurologists, had blood work done, MRI's, Catscan's, Physical Therapy, etc...She refuses to help herself. The physical theraist actually quit because he saw such great progress when working with her, then caught her "faking it", when other people came into the room. She literally acted like she couldn't walk, yet when it was just her and the therapist, she was walking over hurdles. Every morning it is a fight to get her to take a shower. When we get her in there, and we leave her unattended, she only lets the water hit her, and usually lets the shower run and gets out and sits on the toilet until we come back in. She refuses to change her adult diapers. She urinates in them until they leak all over her clothes, and onto furniture. Sometimes she defecates in them. When she does that, she locks herself in the bathroom and tries to hide it. Obviously we find out, and when confronted she says, "It isn't that much," or "I don't know who did that." Recently, after she defecated all over the bathroom, I had gotten upset and hollered at her. "Why would you put your hand in a dirty diaper and touch everything around you!" She smiled at me and told me to clean it. I told her she was crazy and if it was so funny, she can clean it herself. She then attempted to swing punch me in the face, missed and instead made 2 claw marks on my face from the start of my jawline, to my chin. In doing so, she almost fell backwards. I grabbed her so she didn't fall, and began to dig her nails into my wrists until she broke the skin. All the while she said, "You'll see. You'll see." I immediately called my mother, uncle and her sister to help me. When she saw my uncle he asked her, "What are you going to do if we call the police on you?" She said, "That will be fine. I will just say she hit me first and they will believe me because I am old." When her sister walked into the room, unaware that she was eavesdropping by the door, my grandmother began acting confused and said, "Oh. What are you doing here. I don't know what is going on? Are you gonna take me home."
If I didn't know any better, I would think she was doing this on purpose. She also refuses to eat unless she is served. She tells others that she can't get to the food. She can't reach. She cant work the stove or the microwave. Meanwhile, just last week, when her son (the Golden Child) arived for a visit, she got up, went into the fridge and started cooking him pasta and shrimp. Here is the kicker, SHE IS ONLY 78. HELP!!!!