My Mom has always been controlling. Any advice?

She was a school teacher for 20 years. Even tho she was nice to her students, she became verbally & physically abusive to my brother & I. After she became 80, she gave up the will to live. Our family had our own business since 1948 from her father. My father started in 1956, my brother, 1979, and I started in 1981. Since my mom was a teacher, she retired. She came into the family business with my dad and did nothing but watch tv in a back office. Since her controlling behavior interfered with business at hand, she wa interferring with progress. Thus, the back office. Then she retreated to her home. She stayed in bed, smoked cigs, even tho she had emphysema. When she gave up, her oxygen levels were dangerously low, on top on malnutrition & dehydration. Rush to the hospital & then to rehab, she went back home with oxygen machine, oxygen meds, & a visiting nurse once a month. 2012 our family business was forced to shut down do to emmient domain by state for the installation of an interstate. At the same time, my father needed hip surgery, he had to put it off due to the cut off date the state gave us. I ended up dealing with most of the transactions, my father unable to walk well & was torn to look after mom. My computer crashed which made my job very difficult in trying to sell the actual business on my own. All said & done, we finally closed on Aug 7,
2012. We were given until Aug 31, 2012 to vacate! We all go home with no jobs. We couldn't even get unemployment benefits!! Meanwhile, my bedridden mother is ordering my dad to fetch this for her, becoming her servant. Not good for a hip that was getting harder to walk on. Therefore, he fell & fell & fell!!! He gets pneumonia. Becomes bedridden & dying! My bro & I help them until we called 911. My father was rushed into surgery. He had punctured his lung from falling, turned into Empyema. A deadly infection to the lung. He had 2 surgeries to remove invasive material. Almost died the 1st time. I in hospital 2 months & rehab since. Meanwhile, my mother would not get out if bed! My bro fed her in a.m. then visited my father. I stayed with my father all afternoon, then brought dinner to mom. This was tiring, but what choice did we have. After moving dad to another rehab, during horrible fights with my mother not wanting to leave the house, she finally moved into a facility with dad. She was suffering dementia. We had a rev living trust which made me POA & Trustee. This was not easy! I had to prove both parents were financially & personally incapable by having 2 doctors for each parent written & signed officially by the MD's. My father was pushing me to do this constantly! All of a sudden, my mother turns mean! She thinks I'm stealing her money! There is nothing I can do, unless they revoke the trust & have it re-done! I am trying to do everything in my power to keep them taken care of and keep other costs down. She became so ugly & sick that she told my dad that after they were divorced, he could marry me! I was beyond myself, crying all the time, scared to do anything & trying to do things that would suffice her. Nothing worked. My bro & & started meeting dad in the lobby to visit & discuss matters! Her previous yelling in their room had gotten us kicked out. We knew she had Alzheimers. We scheduled a thorough test on Aug 26, 2014. Right after her test, she started to get out of the room & visit people. She still downgraded my father ! I felt soo sorry for him. We even tried to separate them, but dad wouldn't do it. Now my mother has hired a lawyer asked me. I have been fired as her
POA. I still am trustee to make sure bills are paid. I believe she wants me out of the will, but their money will only support them for 6 more years. And to add injury on to insult, my bro & I were guaranteed this money as inheritance for working 35 years in the family business. I have had to hire a lawyer because I don't know what's going on, I don't know if I'm doing anything wrong....and we still have not received the results from my mother's Alzheimers test! Almost 2 months. And just to add another problem, I have Lupus. The stress this had caused has made my body insufferable! I'm suppose to get specialized help. I'm bedridden now, sick, in pain, exhausted, depressed! I have problems/pain in my kidneys. I wonder if I'll live long enough to see this come to a peaceful end. I sure wish I would stop crying, something I never did before. Thanks for listening....