Well, my wife took care of herself and let me be me figuring I would figure it out myself and quit on my own. Well while I thought of it a couple of times, I never did until she came out and said either I quit or she was leaving, well I quit, but she's leaving anyways, says she hasn't loved me for five years, and while I love her, even more now that I have been sober for 38 days I can understand why she can't let me into her heart again.
I do have a hard time that she won't try to live with me sober for a while and give me a chance but I guess our whole marriage was a chance. Now I leave my drinking and my divorce up to God.
What you need to remember is it is NOT your fault, substance abusers blame everyone but themselves and will not quit until they have hit bottom or decide deep in their heart to quit.
You have a hard situation because you are surrounded by substance abusers so I think you should get help for yourself first and then decide where to go from there. I think a psychiatrist would be a good place to start as well as possibly some substance abuse support groups that are out there. It doesn't sound like your church is very helpful, maybe you should find another one.
Well I'm certainly no expert but do feel pain for your situation, I hope this helps a little.