Reimer was not injured during the robbery but his lawyer Lynn Hughes said he had a knife held to his throat by the posse's ring leader.
"You relied on your strength of character rather than addressing the issue," Judge Gerard Winter said.
"When you returned to New Zealand, you buried the trauma of that event deep inside yourself."
In a "frank and honest" affidavit, Reimer described how four months later on a work trip to Singapore he woke up in the early hours perched on the edge of a balcony in his 21st-floor hotel room.
"You felt as though the walls of that hotel were collapsing in on you," the judge said,
Frightened by his psychological decline, Reimer became reliant on alcohol to calm himself and eventually got hooked on meth.
Through his affidavit, he told the court how he mostly used the class-A drug while he was overseas and it led to him becoming more reclusive and withdrawn.
A forensic psychologist eventually diagnosed him as having post-traumatic stress disorder stemming from the armed robbery.
On the day he was caught at Auckland International Airport, Reimer was about to begin a six-week period of extended leave.
Ms Hughes said that was the reason for the large quantity of the methamphetamine, which he had bought from a Los Angeles taxi driver.
Judge Winter accepted it was for personal use but warned the defendant his actions had wider consequences.
"It's clearly a breach of trust," he said. "Crew members receive preferential treatment at borders and when that is abused by one of their own, they make movement at borders all the more difficult."
Reimer received discounts to his sentence for his extensive rehabilitation efforts and two clean drug tests he provided to the court.
He will serve his home detention sentence at his home in Pukekohe and will continue his new job in supermarket construction thanks to the support of his bosses.
