How to handle dramatic family members during parent’s illness?

Helllo, thank you to everyone who has helped me with advice on my other posts. I am just beyond exhausted from my sisters’ constant attacks. My mother has been in and out of the hospital; I have been primary care giver for my mother as well as being a full time employee and a mother to 5. I asked my siblings for more help and in my sisters normal fashion she turned it on me. She told me I need to be on them more?! I have explained I don’t have time for that because I’m doing everything else... while in the hospital I saw my mother every night after work because everyone was “too busy” to be there. After one night of exhaustion I asked for help... after no one responded I said “I’ll cancel my plans and be there” well after I said that my sister in law said she could come for a short time and I told her it was fine I already made arrangements. My sister took that time and while on a call with my siblings said I was refusing to allow people to be with my mom. I am at my wits end I am not going to be attacked for caring for my mother. She had the nerve to come while I was at my mom's house and start attacking me because I told my brother I didn’t see her “schedule” She wants complete control over my mother’s assets and also wants my mom in ltc because she doesn’t have time to give. My mother has made it very clear she wants to be home to gain her strength...How do I handle this? I already blew up on her today because she told my daughter to shut up... but I don’t want to cause my mother more stress. My sister blames me for everything and is trying to get everyone on her side. I’ve told her I have no interest in a relationship with her and she keeps sending unwanted messages and comments... sometimes I want to reply but I think it’s a wasted effort. Any suggestions?