Caregiving is a killer. I need ideas.

Caregiving is stressing us to death. I cared for my husband for 8 years till he passed away in 2009 from early onset dementia at age 61. I then transitioned to caring for my parents, Mom in a nursing home and Dad suffering from cancer- needing treatment and multiple dr appts. Mom passed in 2014. I took Dad into my home full time after he fell the same year. At the time, my 2 sisters were living with me and the 3 of us shared responsibilities for Dad. My younger sister has multiple medical conditions and my older sister had grand parenting obligations as well. During the last 5 years I also suffered with a second diagnosis of breast cancer. To say this has all added up on us is an understatement. In the meantime, my nephew (younger sisters son) was struggling financially and I bought him a pickup so he could work, etc. he does construction work- carpentry, tiling, plumbing, etc. When I wanted to redo a bathroom, I offered him the work. I paid him every day $2-300=trying to be very generous. After halfway through the project, he “blew up”-suffers from ADHD that he refuses to treat. He screamed at me, called me a mother f...Er and I threw him out. He was screaming at his mother and everyone in the house. My now 94 year old father was horrified. I told him to take all of his belongings and never set foot on my property again. I must add, he has had difficulties with many members of our family, creating major rifts between them but I always thought it would be different with us. I helped him pay his child support and kept in touch with him when he was in prison. My sister knows her son and his problems. She knew he was never to come on my property. Last week, she got a call (she now lives elsewhere) while she was here caring for my Dad and I heard her say” well good, now you can come see Poppy”. Next thing, she was asking me if her son could come in because he missed “his Grandfather”! This incident happened 2 plus years ago!! She knew I would not create a problem in front of my Dad so I walked by her and said “three minutes”. As I left the room, I saw he was already in my house and she handed him money!! That was the real reason for the visit. I sat in Dads room waiting. After 12 minutes, I went out and caught my sisters eye. She knew why I was standing there and got up so her son did too. As he walked by me he called me a b*tch and a dozen other horrible words. I told my sister that he was not welcome in my home and that she created the problem. I further said that if he came again, I’d call the police. We have not spoken since. Each of us has assigned days to be at my house to care for Dad. I have twin grandbabies and I watch them 3 days a week at their home. My older sister travels away for 4 days a week to care for her grandchildren. Not speaking to my sister is uncomfortable because we have always been close but her life is full of drama and I do not want it in my life. She has now texted to my older sister and me that she is having major surgery soon and will be unavailable to help for 6 weeks. We will figure out my Dad but I feel very bad for her going through this situation but, I am not willing to re-ad her drama to my life. We had stopped talking a few years ago because of her daughter and finally when this happened with her son I told her I did not want to hear either of their names in my home, let alone them. How do I deal with this estrangement especially because she is at my house from 9 am to 10 pm every time shes here with Dad? I am not comfortable in my own home. I really believe we are all suffering because of this obligation with my Dad. Moving him out is not an option. She has forced me to treat her like I never thought I would. But, the elimination of the stress is very welcome. Help! I need ideas.