I am starting to feel a bit suspicious about your wife. There is a possibility that she found someone first. Not that she might not have thought about leaving a million times before. But something about her reactions to you stopping drinking seem off to me. She seems too cold and too distant about it almost like it was her best excuse for leaving and she doesn't know what to do with not having that excuse now. I hope I am wrong.

If that turns out to be the case, you can't give up on being sober. Even though her leaving might have been the initial shock that got you to stop drinking, now you are doing it to make your life better. Just be prepared to keep your eyes open with her. It isn't uncommon for somebody to start something with somebody new and then use their complaints with the relationship as an out. I know the drinking was a serious problem for her. I am not saying it wasn't. Of course it was. But she stayed for 15 years so why leave now? Either it took her 15 years to finally get the balls to do it or else she cheated. Since you know her really well, I think you'll figure out which it is really fast once you are looking for it.