Very sorry to hear about your loss.
Also, very sorry to hear about the poor relationship with your mother. You could be writing about my situation. Everything revolves around her. She's suffered from low self-esteem for most of her life, apparently brought on by how her mother treated her. Has she done anything to improve this? No!
Coupled with declining health (now 88), some through self-neglect, it's now worse. All she wants to do is talk about how badly everyone's treated her. Last weekend I visited and walked out. Another personal verbal attack on me. Main problem is she will not talk to people who have upset her. Instead, I'm seen as the punchbag. The trigger this time, something her neighbour said to a stranger and my aunt (her sister) telling her what to do (an ongoing theme). Then new cleaner not dusting a table.
What she doesn't know is my brother and I have talked. He's experienced same problem. We're fed up of being told to laugh it off. It's happening too often to be a joke....