Agm,
I get that you can't imagine life without her and that you love her. I couldn't either. I was 15 when I started dating axh, 34 years together. Talk about codependent.
I tried everything to get him to be the person I felt he should be. Kind, helpful, loving, caring, compassionate, and trustworthy, instead he was a liar, cheater, selfish, angry, self absorbed, self centered, pissed off addict.
They are who they are. Once I accepted what Gods plan was for him and got out of the way, serenity took over in my life. It was not my responsibility to fix this broken man, as much as I tried. (And boy did I try) One of my favorite quotes. "God doesn't need my help, as he can help each and every addict who reaches out to him. "
IMO Advising her of her wrongs is really not going to get you anywhere. But there is a lot of help out there for you, if you are willing to do the work. Keep reading and posting, it will all sink in.