Grandfather (96) is going crazy with dementia. Any advice?

I'm 22 taking care of my grandfather, I'm use to it my dads out fishing. Anyway my grandfather finally came back home from his daughters place since Easter, they're bad. They take his money and he doesn't care asking as he gets a drink they won't tell him they keep pretty much most of it. My dads brother tried killing him with a huge kitchen knife, 9 holes on the door the cop said if he held the door closed with his back he'd be dead, the dude got off with I think a misdemeanour. Pretty well nothing. It's cause my dad moved back home and had my grandfathers debut card cancelled so they're all mad at him and us. They can only get money if they bring him to bank. But I can't do much cause it will be really bad and my grandpa wants us all to be together which won't happen. Anyway I got him back yesterday, today he's been acting weird, he's deaf and blind but he said he sees people in his room, ei: a bartender this morning, and said he thought he was in town and not home. Now he sees a bunch of people all around him just standing there and not talking, he's drinking but he's never acted like this drinking. I have nurses coming over Monday but anything I can do to get his brain back to normal? I'm not sure if they always have him his pills but the pills are just Tylenol and depression pills. But I've never seen him like this, my dad has when he got him back before too.