You're understandably upset right now, but be careful about comparing out. I know it's hard because most of us are trying to help each other through sharing our personal experiences (and not telling one another what to do), and when we identify with the experience of another it's tempting to compare... but no matter how similar an experience may be, my experience is my own, and yours is your own. When we let comparison into the party, his old friend self-pity usually tags along, and that does nothing to help us.
Some relationships survive, some do not, and addiction is not the only force that determines that. I think what others have already said is most important: the goal is for us to make decisions based on what we really feel, without guilt, without others saying what they think we should do, and THAT is only possible after we clear out all the muck that's been clogging our engines for so long. As a personal testimonial, I can only be grateful for the painfully illuminating light that I encountered in my Nar-Anon groups (which then led me to a year of very important personal therapy) and here in SR. It was painful because, in a way, my eyes had never experienced sight before. I truly was blind, but now I see.
Sending you hugs.