The key is that he needs to learn that he has come to the end of the road. He needs to learn he has no solution for life and needs an alternative coping system based on 12 steps of AA to cope with life
His solution of coping with life through bottle has resulted in disaster. He cannot handle his feelings without a drink and no matter what steps he takes with the thearpist, he will not succeed until he quits drinking.
He have to learn that the new coping system is based on spirituality. Having higher power is essential for his spiritual recovery because his ego needs to be right-sized until he reaches a point of humility where he learns that the universe does not revolve around him.
The memories that trigger the PTSD will be wiped away with a through spiritual recovery program. It is essential that he needs to start a seeking spiritual solution and an exit from alcoholism The solutions in the rooms and finding solace in alternative spirituality like Zen Buddhism.