I have a friend whose drug of choice seems to be terrible choices in men and the ensuing drama. When we are together now, I find that she gets on my nerves like crazy and all I want to do is snipe at her. And then she says something crummy back to me.
And I have had to physically remove myself from her presence because I no longer choose to fight with people. I own my part in it, but if I can't control my triggers with her, I owe it to the friendship not to do further damage by trying to be around her. Her negativity and constant complaining get under my skin, too, and I get to choose if I want to be around that.
I would LEAVE a friendship that was as overly-enmeshed as the one you describe. None of you is doing any good for the others. Give it a break and maybe when he comes into recovery, you can try again. But seriously? Let this one go. He can sink or swim without you.