Hello to Mechuen from a PFLAG mom...
I would very much echo JJJ's comments to the effect that you seem to have a remarkably clear-eyed view of what's transpired in your relationship over the past few years. Addiction is an insidious and evil thing. It creeps up on folks but, as so many others have noted, in the end it's always moving forward, not back.
It's terrible what's happened with your partner. We can sympathize and empathize but as you realize, we can't fix. Not a mother's or father's, not a spouse's or a partner's, love can fix this.
I'm wondering if there are resources in NYC that might be geared specifically towards GLBT folks. (I seem to recall there was a special initiative that dealt with people using crystal, for instance.) Might GMHC have a place to start? And, I know that AA and NA have focused groups, where you would be able to find people in a very similar situation to yours. Those are also good places to find referrals to therapists who are sensitive to the issues and can give special care.
It might be that eventually you'll need some support in figuring out what to do about this relationship. I really do understand about the social isolation... over the past few years, my friends (and my friends are important to me!) have gotten sick and tired of hearing about my AS. I feel more and more lonely as I find that there is a huge part of my life I can't share with anyone. I have even lost a friendship over it; the person had problems of her own and told me flat-out, I can't listen to you anymore, and it was a time when I turned to her in utmost distress. Now we are cordial but that's about it. I have found that I have to turn to people in Al-Anon or at least women in analogous situations, because other friends don't want to hear about what they're powerless to fix. Hmmm.
This is a great community for sharing and support, but there is also no substitute for in-person help and hugs. A big cyber-hug to you anyway!
Jane
p.s. My PFLAG mom status comes about due to my daughter who is a fantastic and healthy kid, not my AS! Just wanted to make that clear!