I have been best friends with her for years - I take her to her appointments, shop with her, travel with her, etc. Both parents live independently but have needed more help in recent years. I also have a sister who we believe has undiagnosed manic depression and we all tread very carefully around her. I recently made a decision to cancel a party at my home and my parents were very upset as it would make my sister angry. My mother became unreasonable with me, saying that everyone hates me, I have broken the family, and that she wants nothing more to do with me and my family. I cried hysterically, groveled, tried apologizing to everyone, all to no avail. She was stoic and mean. My dad even tried reasoning with her. A few days later it got worse when I even mentioned that maybe there was the possibility of dementia, because her attitude was SO UNLIKE my mom. My mother would never let a child cry in front of her without reaching out. Now we are truly banished. I am at a loss. I think my dad knows something is wrong but if nobody will admit anything, there is nothing I can do. My sister is filling her head with all kinds of hatred and I can't even get in there to try and figure out what is going on. I don't know what to think. Oh - also, she had a major stroke around the age of 43 and her mother had Alzheimer's. Any advice you could give would be appreciated. I am heartbroken.
Get mom to the doctor and diagnosed WITHOUT mentioning the word 'dementia' to her. They say that Alzheimer's tends to be hereditary and I can tell you that all but a couple of the 8 children in my mother's family had dementia and/or Alzheimer's when they died. The other few died too young, before dementia had a chance to set in.
Take a non emotional look at what's happening here and use your head instead of your heart, at least for now. Help dad help HER in any way you can, by getting her to the doctor asap. If it's a UTI she's dealing with, it'll be over with once the antibiotics are administered. If it's dementia or Alzheimer's, it's better to know than not.
Wishing you the best of luck moving forward.
She needs to be seen.
In the meantime, respect what she told you until she can be treated and stay away. It is not unusual for an Alzheimer's patient (If that is what she has) to pick a family member to falsely accuse of everything and reject that once favorite person. If you stay in contact. her thoughts about you will increase. imo.
Try not to imagine what your sister has done or said if you have nothing to go on.
Focus on your immediate family right now. Who is the "we" you have said are truly banished?