Your decision to end the relationship sounds as difficult to make as my ex partner’s decision to end ours. I don’t have addition problems, but my mental behaviours have become more toxic over time. We were together for 20 years. There were issues on both sides of the relationship that could not be resolved. I have recently been looking into Childhood Emotional Neglect, following the death of both parents last year. I was starting to make some progress, but too late.  You did the right thing for you. It may well be the right thing for him too. The shock of the ending is hard to get past and you have a head start on him with that. He will try to cling on to what is familiar, to what is safe. I did the same. In some aspects I still am. Stay with your decision, give yourself the time and space to look after yourself and to heal. It will be hard for both of you but you have to stay strong for yourself. I have learned to focus on me and not ‘us’ anymore. He will get there as well. Much love to you.