Hi whatsgoingon, you describe what Alcoholics Anonymous calls the mental obsession quite well.
" There was a tremendous urge to cease forever. Yet we found it impossible. This is the baffling feature of alcoholism as we know it - this utter inability to leave it alone, no matter how great the necessity or the wish."
" But there was always the curious mental phenomenon that parallel with our sound reasoning there inevitably ran some insanely trivial excuse for taking the first drink. Our sound reasoning failed to hold us in check. The insane idea won out. Next day we would ask ourselves, in all earnestness and sincerity, how it could have happened."
The way forward for me was first to try and quit on my own. When that didn't work I tried therapy and treatment(loony bin). When that didn't work and I was out of options, I grabbed what AA had to offer with all the desperation that a drowning person siezes a life preserver. That worked.