I really sympathise OP and you're not a terrible person. My mother is in her 80s and is being a bit difficult.
She refuses to go into a care home and has told her (temporary) carers not to bother coming back, but then complains that she can't do things.
She has a lovely neighbour, who would check on her and help her with things but she's convinced that anyone who tries to help her is 'bossing her around' and the neighbour is now described by my mother as 'a bossy boots'.
She is practically housebound, can't clean, can barely cook or look after herself so it falls to me and my DP to run errands and try to support her.
My brother is useless and despite living less than five miles away from her, refuses to see her. When I offered to pick him up, take him to see mum (he was always the golden boy) and drop him back home, he asked whether she was dying. When I told him that she wasn't, he completely lost interest.
DP and I both work, have three kids (one with ASC) and I only just about manage as I never fully recovered from my Covid infection in 2020.
Last week, I contacted a care company for mum and they matched her with a carer who lives in the next village. She's meeting mum today and I'm currently sitting here dreading a call from my mother.