Barnabus, something about your posts reminds me of of a man I got to work with a few years back. He had a few things going on, benzos, of which I have no experience, alcohol, and this god awful relationship which could only be understood, as far as I could see anyway, as a really powerful co-dependence.
I still don’t know which was the main problem, but I do recall that she did awful things to him, eventually resulting in her being locked up, yet he was like a moth to a flame. He just kept going back. It was so much like the alcoholic and the fatal first drink.
He would say to me “ right, i have ended it for good. I just sent her a text telling her it’s all over.” It was no more than five minutes before he was saying “ I’ll just text her to see if she’s alright” no no we cried, but he did it anyway. Before we knew it 15 texts had been exchanged and it was all on again.
He could see that the relationship was a big problem for him, but like the suffering alcoholic, he could not stay away from the fatal first contact.
I don’t know if that rings any bells for you, but if it does, I think there is a forum on codependency here which might be helpful.