I'm caring for my Mom (77) who's having screaming episodes. What can I do?

I need help immediately. She is extremely set in her ways and has always been paranoid of people. She was commited into treatment/mental institutions when she was in her 40s because she was seeing hairs under her skin. During that time she was drinking heavily and quit drinking after her last involuntary hospital stay. Now she is seeing the hairs again and is constantly brushing and pulling her hair away from her skin. UNTIL we go to the doctors. Then she's an angel. I have no help from either of my siblings because she has told them I have been abusive (physical) to her and they believed her and will not talk to me. I myself attempted suicide because I am at my wits end. A couple days ago, she was very agitated thinking that a friend of mine and myself were scheming behind her back. She screamed for two hours at me and finally went to bed and woke me up the next morning the same way. When she does this, she calls my brother (Arkansas) or my sister (Washington) and we live in San Diego. She couldn't get in touch with them, so I suggested she call her social worker but she called 911 instead. They could see immediately that she wasn't right in her mind and finally, I felt like someone understood what I was going through but they suggested I look on the internet which brings me here. My brother just now started calling my mother again after a 10 year absence. He avoids all responsibility so he is no help. My sister won't talk to me because my mother calls her while I'm at the store or not around and tells her I am mean to her and have been physically abusive to her. My sister has visited my mother once in 22 years and that was for 10 minutes. She calls maybe 3 times a year. After speaking with my mother, my sister has called social services and reported me to them and the police instead of asking me what is going on even though I've had to live with mom for over 6 years now. When I try talking to her she hangs up on me. She tells my mother to kick me out and once the two of them get going my life is a living h*ll. There is no way my mother can live by herself. As soon as I smooth things over with my sister, my mother gets extremely mad and calls her again when I'm not around and it all starts over again. I have nobody else in my family. No children, or anyone else. I had to split with my husband of 20 years when he got transferred because I could not leave my mother alone. My mother will not let me go into the doctor's office with her except for one time and it was to her neurologist. Her neurologist wanted her to see a psychiatrist about her mental problems and now my mother refuses to see her. My mother is on social security with no other income. My mother will not listen to anything I have to say. As soon as I try to talk to her (during her normal time), she starts screaming how much everybody hates me, etc. As I said before, I took an overdose of sleeping pills because I feel so depressed and alone. My mother is seeing the hairs again and now I know she needs to go into assisted living. What can I do to get the process started? What rights do I have to see her doctors? Any help you can give me would be so appreciated. Thanks for listening.