So sorry to hear all this. I saw your post in the other forum.
You've tried stepping slightly inside the doorway, but still listening. Continue to do that and he'l likely coax you out every time. There's a saying around here (and forgive me if i misquote it) but the definition of insanity is doing the same thing over and over expecting different results. If you're serious about ending it, try closing the door completely. If you've made the decision that its done, you want out, then you should just leave. I wouldn't discuss it, answer the phone, read texts, make a "move out plan" etc. It sounds to me like hes very good at manipulating you. Addicts typically are 'geniuses' when it comes to arguing and lying etc. etc. If you give him the opportunity to, he will. for sure. and the cycle will continue. You've trained him to bank on the fact that he can be an addict and you won't leave him. So why would he want to get clean when he can have both?
Realize that you're better than that, that detaching doesn't mean you don't love him just like relapsing doesn't mean he doesn't love you.
It sounds like you know that its all in your hands. You have every ability to answer your own distress call. The people here will help you see how.
hugs