Off the top of my head--the disease model of addiction. My daughter is the (recovering) addict in my life, and once I realized that I could not manage her disease--that she had to do that and choose sobriety for herself--I accepted my situation as the mother of a child suffering with the disease of addiction.
This did not mean I then enabled her disease (once I realized what enabling meant). I had to accept it as a permanent part of her, and once I did that, I felt a little more at ease. Not happy, definitely angry (at heroin, at our culture, etc.), and those two uncomfortable feelings made me take better care of myself. I learned to make healthy boundaries and painful decisions related to how her addiction impacted our family--like telling her she could not come home or contact me again until she was ready to go to treatment or was sober for several months. Off she went into the streets, a homeless addict. This was the hardest time for me but it is also when I grew the most spiritually. NarAnon meetings helped me immensely--a safe place for other parents and spouses who were walking the same journey.
Thanks for asking, HopePrayLove. It was good for me to reflect on this today. 18 months later, my RAD is back to her best self--the one I adore--and I am grateful every day she is sober. I will never forget where we've been, though, and wish you all the best in your struggles today.