Anyone out there have experience with the heartbreaks of substance abuse past or present with a loved one? Can you get through to them? How?

What happens when you dont want to walk away but youve already made all the mistakes of trying to control it and them and the whole thing is breaking your heart and making you crazy?

Has anyone not walked away and worked it out eventually? How do you manage the internal and external upheaval of the situation?

For reference Im talking about alchohol, and various 'other', not a thing like crack or heroin, more a 'sensation' addiction or painkilling. There was no violence in the home and no abuse directly except the traditional irresponsabilities and disappointments of living with alchoholics, which are plenty.
I cant solve it in my head and hes still on my mind and real close by. I lived all the good parts and Im not a quitter, but.... this is a sudden resurgence of belief that being 'in party mode' is a good thing and I guess any semblance of 'normal' life is not.

Any advice welcome.