Welcome and you are SO not alone.
I am going through very similar feelings and situation. And because I am standing here with the fresh collateral damage at my feet from being with an alcoholic/drug addict for three years, I don't quite have a lot of wisdom to share with you... just empathy, compassion, and a deep understanding of what you are feeling and dealing with.
I feel like a walking wound who has lost EVERYTHING (almost my very life) and HE is living his life, with a new woman, without any responsibilties to our daughter or the wreckage that his addictions and behavior created. He even said to me after he got clean and right before we broke up that he had forgiven himself for everything, was moving on with his life, and starting fresh. That he had closed the door on the past. No amends. No financial restitution. No "how can I make things right". Nothing. He didn't even remember most of what happened while we were together, because he was blacked-out or on so many pills.
So, the rage that I feel right now around being left with all the raw and vivid experiences and memories of everything that happened and being left alone to raise our daughter, is sometimes unbearable. It truly feels like there is no justice sometimes.
Anyways... one minute at a time, I am trying to pick up the pieces. It's a long process but at least now, I have the space and room to do healthy things for myself as much as I can. And at least I have this forum for support. It really does make a huge difference talking to people who really GET IT.
Wishing you peace, ~Sasha