Paranoid Disorder. Need help asap!

She feels that other people are constantly conspiring against her. Does not trust anyone, including her children. She is hostile towards everyone. Gets angry easily. Does not take criticism or respond to rational arguments. Socially aloof and distant. She thinks up random stuff and says that somebody told her that (I think she is hearing voices). Because of her paranoia, getting her to psychiatrist and giving medicine is difficult. She has a history of depression (20 yrs. She was earlier taking medicine for it but has stopped for a long time now ( 6-7 years i think). She stays alone now as she does not want to live with my siblings or me. My father passed away 11 years ago. Sometimes it looks like she is really sick and sometimes that she is faking it, as she behaves very intelligently and calculatingly. She behaves mean and selfish. She has BP problem. When she gets angry, which she often gets by getting into arguments with others, it goes up to 190/120. I am worried, need help asap!