When I've gone through withdrawal (either for opiates or alcohol) I used to remind myself that every second of pain and discomfort was one less second of pain and discomfort. That each second, I was getting better. Each second, the poison was leaving my body, and my brain and nervous system was learning to do without.
That withdrawal was the body healing itself. Can you think of yourself as healing?
Conversely, I reminded myself that if I put anything back in my body (drugs or alcohol) I would immediately stop that progress, and hit "reset." And I would be forced to endure it again, and probably worse.
Yes, the lure of the short-term relief is maddening. But all it does is delay the pain, which must be paid.
So why not now? Pay it all, NOW. This time.