qazqaz

Any tips on how to play out this story gratefully received... I'll scribble out the whole story:
He's been on the aa path for 8yrs and relapsed 2 or 3 times, once recently (ended up in hospital. DTs) after hitting rock bottom.

He tells me intensely that I am 'the one' and talks of marriage and kids... even though we've only really known each other for 2 months & most of that has been the emotional rollercoaster of me telling him to change and him talking about himself or his fight for 'us'. We knew each other vaguely years ago, but never had a great connection then. I wonder whether he just sees me as a kind, gentle person that he needs, or that he convinces himself that I am his perfect match because he wants me to be.He tells me my own future dreams about living abroad, but with him on board, as if telling me what I want to hear.
I find myself sucked in by his poetic talk of future happiness sometimes, despite promising myself I wouldn't. I give in to his persuasion to give him a hug, a kiss, tell him I love him (although that's not in the way he wants me to mean it).
My head tells me strongly that I shouldn't get any more involved and should step back, but whenever I try to tell him to walk the path on his own he tells me how I'll lose his warmth etc. and tells me that he's given me everything and has nothing else to give. He also wants me to state whether i'll be going for ever or if I'll reappear shortly to jump onboard his dreams of our happy future.
I bumped into him again the the other day and we always have the same circular converstation of his 'hold my hand and then I'll make it' and my 'take some steps and then i'll hold your hand' and 'take some steps and then I'll think about holding your hand'. I appreciate my changing the goal posts here didn't help him, but it was me reacting to the extent of his illness as I discovered it.
I want to be the good friend, the rock, but he makes it black and white, saying that either I am beside him, maybe as future wife, or I leave his life and we'll never be in each others lives at all. I do want to be there for him, I even said once that I wouldn't be another person who ran away scared of the turmoil in his head; turmoil that he doesnt want. I can't bear to not be in his life in some way, knowing that he's doing allright at least. I know that if it weren't for the illness and associated problems we would be dating and I know that I don't want to lose him from my life, but I have to listen to my head and not get involved.
He has the alcohol down as the problem, but I wonder if it is a symptom.
I just want to help him balance out. I can't imagine going through what he has and suffering as a result with addiction and struggling with relationships. He never signed up for any of it. Seems so unfair.
I guess the question is, can I angle being just a good friend or do I have to do the hardest thing and leave his life, never knowing if he's allright, never knowing if someone was able to help erase the mental/addiction issues and allow him the happiness he so deserves?