I just want to say that you really need to stress how difficult things are.
My dm was supporting my uncle at home when my grandmother died. He had Down syndrome and his behaviour was getting bad, even though he had always been a dream to be around.
After numerous phone calls being told nothing could be done for him, mum phoned and said ‘if you don’t come and get him he will be on the streets this afternoon’ (she wouldn’t have done that really). Within 2 hours she was phoned and offered 40 hours of support a week. 40 hours! When apparently they had nothing for 4 years. Unfortunately it was too late, mum was at breaking point.
Mums siblings lived over 200 miles away, and my siblings 150-350 miles away, so there were only the two of us. Me with two dc under 10, and working around the UK so could be away up to 4 nights per week. So 98% fell to her.
He was put into a supported living home. It was the best move ever. Realistically he should have gone in years before. He benefited so much. But my theory proved to be correct, although the social workers argued against me for over 18 months saying I was wrong, he was diagnosed with dementia. So he was in the right place that could provide 24/7 care.
When he passed away I was eaten up with guilt, because nan made me promise the day he died that I would not let him go into a home. I felt like I’d let her down. But I know in my heart of hearts it was the best place for him (regardless of the opinions of so called ‘family’, you know, the ones who like to bitch about what you’ve done, but never once helped out?). So please OP don’t get eaten up by guilt of what you are planning to do. Having worked in this area, worked with staff (I was a training manager), I can hand on heart tell you how much vulnerable adults benefit from a supported living service. If you are lucky enough to be offered the funding and get an option, make sure you visit and get a real feel for them, before making a decision. Sorry about the essay! Good Luck.