day 5 is early, but these are the hardest times. days will turn into weeks before you know it. i'm sure on day one or two you were counting hours.
the receptors in your brain are sitting there idling, waiting for the "usual" fix. well, it ain't coming. so they start sending strange signals throughout your nervous system, which we interpret as urges to drink. eventually the receptors that are used to receiving the fix will get tired of waiting and re-adjust, thus the recovery process.
the human mind is a pretty cool toy, but it's a very fragile one as well.
the only thing you can do now is to resist that first drink and ride it out... it does get better and easier with time. we are naturally wired to adjust and adapt.