@Helpmeout99 honestly, you could have written the ChatGPT version of my life before going NC and then moving to very low contact.
I have read all your responses, but not had time to read all the contributions from others on MN so apologies if I repeat. First off though, well done for the 5 months of living with this. The tension in your household must be extreme.
Second, you won't be able to avoid the conflict indefinitely - sadly. In my case it blew up monumentally, in others people have managed to let it drift. But my advice would be to go NC or very low contact for 6 to 12 months and if you can go through some counselling to support you make the break then I would absolutely recommend it. It is heartbreaking. It hurts and it takes a long time to undo all the conditioning and question the gaslighting. 12 years on I still find myself periodically dragged back into the drama cycle.
But what you are experiencing is not unique. It is not you or your beautiful family. You are not responsible for your Mother's mental health or the causes of her actions. How she is behaving in your own home is not acceptable and you wouldn't tolerate it from friends, a partner or a child. The energy you are committing to propping her up is taking it away from the people who matter most.
For me, the final straw was not wanting to drag my family into someone else's problems. What is the phrase? Not my circus, not my monkeys. I needed to be able to role model and build healthy relationships away from my M for my children's sake.
This won't go away (I posted not so long ago about old age and mother issues) but you can learn to create boundaries and hold yourself to account for maintaining them. And it will continue to hurt. But - over time - the hurty bits get less frequent and the bits in-between are good. Just don't lose sight of yourself in the process.
Someone recommended the Out of the FOG website to me (recc came from here). It is good. Other things I have found helpful are (a) counselling first and foremost (b) books on toxic mothers and (c) talking about it. In terms of the latter not everyone will understand. Your wider family may be difficult although it sounds like your brother is well aware so that might be a good place to start along with your DH. But you will find friends who are in a similar position. The issue is we are so conditioned to never question our Mother's. I remember being told I was being ridiculous as she was my only Mum. I had to point out I was her only daughter and she had already lost her only DH as he divorced her. (Ironically, DH married again to the most wonderful SM and I have 2 Mum's... plus a great MIL). Anyway I digress. The issue is we are so conditioned to have perfect Mother - daughter relationships that we rarely tell people when they aren't functional. Choose who you talk to wisely but talk. Don't hold it all in. We get you. We understand you. And it is not you.