I never know when she will say something mean and hateful to me. She has been like this her entire life. She has hit other patients and called them nasty names. She doesn't seem to care if I visit or not. To be honest, it is so upsetting after I visit, I have nightmares and flashbacks for weeks.
The only thing you are obligated to do is take care of yourself and your family.
Remove toxic people from your life, it is not healthy to continue to deal with this type of person who will never change.
I don't see even being legally responsible for them makes you obligated to visit. I think even a Guardian only has to see a Ward all the time. Just needs to see them a few times a year to be able to say they are safe and well. That they have been seeing doctors regularly.
Mom has Dementia, she may not even know who ur. But seems you trigger something and that may not be good for her. She may get so agitated she is a problem for staff after u leave. And if she is hitting and cussing other residents out, I would ask why she is not on medication to calm her. No, you are not obligated to visit.