Calvin, so sorry you're in this position. At this point you need to protect yourself as it's vital you don't go under. Sometimes you need to accept you've tried and take time out, knowing there will eventually be a crisis but that will not be your fault as you have tried.
I've had a nightmare with my Mum this year. My Brother lives abroad and has not seen her for 4.5 years. She was getting worse and ended up in a CH pending a Best Interests meeting. The first time my Brother spoke to the SW he told her I was trying to protect my inheritance. I was Attorney for finance at the time and it was a very serious accusation, plus I have children and I think if the accusation was found to have substance there's a good chance Children Services would have been notified.
DH and I were working for my Brother. He effectively fired me and said he was reducing DH's days. Mum told SW I was evil and plotting against her. Then later that I was trying to sell her bungalow to get money and I had encouraged her to complain about the daily carers. I have requested I am written out of her Will which is being done and resigned as Attorney on the finance POA to protect myself against further accusations.
My GP has been great and told me I must not be involved in Mum's future care due to the effect it has had in my health. SS have said the consider I have acted in Mum's Best Interests at all times (I always did what the health professionals told me) I am starting to rebuild my life which quite frankly was in bits and I will be having counselling.
My Mum did well in the CH with correct meds, hydration, food and care. She has now regained capacity and is home with live in carers. My Brothe has still not come over but is arranging the Health and Welfare POA and will be sole attorney as for the finance one. I did have a call from Mum this week on my Birthday and have agreed to go for a cuppa if she rings to arrange it (apparently current carer is nosy, there is dust in the air so she wanted to wait till the new one). I've said I will not discuss what she said about me in capacity assessments as not true and very upsetting.
Possibly we may regain some kind of relationship but I will never be involved on her care again. I can cope with the nastiness of Dementia but when a sibling turns on yours my Brother did, that cuts deep. Looking back I would have walked away sooner to protect me and my children. I'm sorry to go on so long but please learn from my experience, protect yourself. You can't change other's behaviour, just how you respond to it.