I've heard that the usual craving for illicit substances or even litcit ones (cigs, booze) lasts about seven minutes.
It can feel very urgent, very RIGHT NOW! - but it will pass. I have been known to give in, though, in those awful seven minutes. It only takes that long for me to get to the liquor store.
But I'm on the water wagon. I feel much better when I am.
I"m really not afraid of drinking and dying - I'm afraid of drinking and NOT dying.