So, I have been living with my grandmother since I was 2, for my mam had to work. At 10, grandmaa and I moved in with mam and the problem began. It's been 9 years since that. My grandmother is currently diagnosed with dementia and the docs are testing her of Alzheimer. She talks alone with someone who's not there. She asks thinks in a whisper and replyies in a louder voice. She started doing this secretly but now she does it openly in front of us. She is manipulative, obsessed with control (when mam or I go out, she leaves her bedroom door open until we're back, no matter if it's 5am.) She says she hears her deceased aunt calling her. She has turned into a food shopaholic and since my mother told her not to buy so much, she started hiding what she buys in her wardrobe. She makes our lives a living hell, insults us, tells us to f*** off, calls us whores and sluts. Once, she said she was going to throw herself out of the balcony and mam and I blocked the balcony entrance so she started to hit my mother and I had to stop her. She wakes up at 5am just to do "house chores" for she says she HAS to help us. We have told her a thousand times that she hasn't have to do anything but she feels it's her way of "paying" us for living in our home (she refuses to call it her home, no matter how hard we have tried to make her feel integrated.) She always says it's not her home but she throws away things we like, no matter if we want to keep it and she does whatever she wants. She is obsessive with order. Back to the 5 am subject, she wakes up at 5am to do "her" chores and wakes both mam and me and gets mad and manipulative if we tell her she woke us up and why not to do it at 8am for instance. She cannot see us resting. If she sees we are sitting in the couch or taking a nap, she comes up with things to do such as do the laudry right now. She HATES it when we are on our phone, reading or using our laptops. It is horrible. Both, mam and I suffer from anxiety ever since this started. We don't know what to do. When her other sons and daughters tell her to go to eat with them, she finds an excuse or downright declines. She refuses to leave the house even for a day because she fears my mam is going to bring a "boyfriend" or "friend" inside while she is out. We don't know what to do.
As your own experience has already demonstrated it does absolutely no good to tell her something a thousand times. Trying to reason with someone who is losing her ability to reason is frustrating for both parties.
She is not manipulative or obsessed with control in the usual meaning of those terms. She has totally lost control of her own mind and her own behavior and it is understandable she tries to impose some control or sense of order where ever she sees a chance.
Poor Grandmother. She can't help having dementia.
Does that mean you have to sacrifice your lives to her disease? Gracious, no! You need help to deal with her needs. Perhaps with a medical treatment plan for GM, some caregiving training for you a Mam, and some in-home help coming in to give you some relief, this situation could work with you all living together, at least for a while longer.
Another option is to find a good care center for her, where they have 3 shifts of trained staff, and plenty of back-up for agitated episodes.
The name calling and the accusations are part of Alzheimer's as well. Your grandmother may not remember saying those kinds of things to you but you do. That's just one reason that makes this illness so horrible.
You said you no longer know what to do. Well, you won't be able to change your grandmother's behavior and it's only going to progress in time. You can move out. Or find a nursing home for your grandmother where you can go and visit with her. There's also a good book called "The 36 Hour Day" and it's about dealing with someone with Alzheimer's. It might give you a clearer picture of what's in store for you and your family.
But if you want things to change at home unfortunately the burden of change will be upon you as your grandmother isn't capable of seeing her behavior as objectionable and changing it.
I think the book is helpful, and YouTube videos (by T. Snow?). Search "dementia or Alzheimers". The videos really helped me and reading many posts in this website gave me perspective, great answers, and most of all showed me I wasn't alone and definitely helped me understand my mothers hurtfull behavior better.
Contact your local Agency for Seniors/Elders -- or your local senior center; they will provide a wealth of information for you and even sit down with you and your mom and help you sort through different options and plans.
You sound too young to go thru all this stress, and mam too (especially if she is working). GM needs more care during the day. Maybe her doctor can prescribe something to help with GM anxiety -- but be careful of too much medication because that in itself makes things worse.