In your situation my plan would be to establish boundaries and goals:
I choose not to live in a home with someone actively abusing drugs.
I choose to trust my own instincts rather than the words and manipulations of a drug abuser.
I will not trust that my loved one is searching for sobriety until they ask for help and demonstrate a willingness to accept help which is all around them if they choose to seek it. I will not support them in their addiction.
I will create a support system for myself by finding a program of my own with people that understand.
I will be seek to be honest with myself about my loved one's abuse of drugs and the effect it has on my life.
I will not allow my loved one's choice to abuse substances to destroy my life.
In short - non of it is about the DA - it's all about you and your choices.