What Dee and Gottalife said. And, what plan are you working? Mine is AA and it's free - rehab wasn't an option since my parents wouldn't pay for it (after all I had put them through). There are others people use with success- the key is having an active plan and wanting to be sober more than you want to drink.
I believe that genetics are a factor- it's certainly rife on my mother's side- but I also believe choices about our drinking factor in, some of us have other mental health issues, and.....so on. It also doesn't matter, because I'm a straight up alcoholic.
Lastly- I'd venture that it's best to focus on you (me), despite loving your brother and daughter and worrying about them. YOUR drinking is what should be your top concern.
Hope to see you here.