If you ever lived with pets (cats and dogs all my life), you may have experienced the phenomenon that, when their bodies are shutting down and they're in their death throes, they perk up and seem perfectly fine for a day or to. Happens with people too. This has always been heartbreaking for me, and I imagine that this has also been the case for others.
This experience is analogous to our alcoholism, and this is only meant as an analogy: The closer we come to extinguishing our drinking behaviors, the more likely we'll have a day or two when we again drink, and everything seems fine. Both you and your alcoholism are fighting for your lives.