I'm so sorry for what you and your brother are going through.
I was in a somewhat similar situation with my alcoholic father a couple of years ago. I can relate to how stressful and frustrating it can be and I was much older than you when I had to deal with it.
I commend you and your brother for all that you are doing.
My dad had dementia and also emphysema. He was in pretty bad shape and also scared when we finally convinced him to leave his apartment.
His situation was different in that he was knew he couldn't live alone, however, I had to find him a place that would accept his minimal income.
I got a lot of advice from eldercare agencies in his state. I think most states have a Department of Aging. I think that's a good place to start.
I kept making calls and telling his story over and over again until I luckily found a place that would accept him. Even then, he was in and out of hospitals and even spent some time in a mental hospital because he became violent after taking certain meds.
During this extremely stressful period of my life, I kept my serenity by realizing that there was just so much I could do. I wasn't going to be able to erase the years of abuse he put his body through and I still couldn't change him (This I tried for almost my entire life).
I made sure that I continued with my own self-care - went to ACA meetings, posted on on-line forums, and met with my therapist & priest. The rector of my church is also an ACA and I got a lot of support from him.
I had to give so much up to my HP.
Thank you for sharing and for letting me share.
Best Wishes,
db