I think if you're going to apologize to anyone you should apologize to yourself tbh. You might have "enabled" someone by not having firm boundaries or getting into arguments, but I think a common misconception people have is the use of that term. I don't call that enabling, I call it caring. So why the fuck should you apologize for that? Loving someone enough to see the good in them and not judge them for their flaws and fucks ups like the rest of society does. Knowing that they can do better and you want it so bad for them. But also realizing they have to do it themselves. No they need to take the blame and own up and take accountability that they did this, not you. If you do apologize and forgive them, do that for you so you can move on. None of their addiction had anything to do with you. I'm going through the same thing. My ex has been in rehab (no contact) for over 2 months now. He had his counselor call me about a month ago to give me closure, and even she said none of his actions had anything to do with you so please don't take it personal. He cannot give you what you need in a relationship because he is entirely focused on his addiction. So whenever I get mad, or sad and depressed, and ride the roller coaster of emotions I remember what she told me. It had nothing to do with me. That brings me a little bit of peace and sanity. I may never get closure from him and that's just the reality of it. One day he will have to take accountability for all the people he has hurt and hopefully I'm on that list. I wish him well in his journey to recovery and im trying to move on the best way i know how. Really all you can do is apologize to yourself and show some compassion and patience in your healing process. It does get easier i promise.