The 27-year-old NRL prop for the Cronulla-Sharks arrived in Christchurch from Sydney with his wife, Nikki, and two young children on Wednesday morning.
Fifita, who is Tongan and Aboriginal, was invited to speak to whanau in east Christchurch ahead of a Pacific Series 2016 tournament at Wainoni Park on November 11 and 12.
Fifita did not hold back as he talked candidly about his upbringing in a state house in Western Sydney, his "troubled teenage life", the harsh realities of his professional football career, battles with weight gain and his descent in to depression.
Starting out with the West Tigers on $1500 a month, Fifita said eking out a meagre income with a cupboard full of two-minute noodles and corned beef was easy compared to the pressure to perform on the field.
"I never realised how much pressure you come under in first grade, you're called an elite athlete for a reason."
In 2013, he enjoyed a golden year, including getting married, playing a record 39 games, being selected for Australia and winning the Rugby World League Cup.
The following year started with a deep sense of emptiness, despite his previous accomplishments, and it "went down hill from there", he said.
The tipping point was a minor altercation over a photo during a night out on the Gold Coast with friends and his two brothers in October 2014.
"I went back to the hotel room and had it out with my brothers and just . . . life was over. I'd had enough."
He launched himself out the window of a multi-storey building, but was caught by a friend before he fell.
"My brother said 'what's wrong?' and I just leaped out of this window. I just did not care, I really did not.
"I couldn't handle this pressure from football any more. I was too big and too strong to ask for help."
Despite the frightening episode, Fifita did not take action to address his mental state after returning to Sydney.
His twin brother, David, eventually asked police to arrest Fifita and take him to a psychiatric hospital.
"He just kept crying and crying and he said 'look, you're my brother and I love you and I can't see that ever again'."
It was the start of his recovery and he later returned to hospital for a second time voluntarily.
"You may be the biggest, you may be the strongest in league, you may be the smallest, but it takes the one with the biggest heart to ask someone, if you're in need get some help.
"Like I said, it ain't weak to speak."
Northland rugby player Kurt Davies also spoke about his experience of depression, saying not "fulfilling his potential with his sport" led him to doubt his own worth and consider suicide.
"Through my struggles I've learned a lot and I'm here to help prevent it because the holes it leaves in families is heart-breaking."