Fifita admitted to struggling badly with homesickness throughout the tournament but he felt instant relief when his newly-wed wife Nikkita and infant son Latu Jay arrived in London this week.
The 24-year-old Cronulla forward celebrated his son’s first birthday on Wednesday, with his family to watch on from the stands in Saturday’s semi-final against Fiji.
“It’s like a big weight off my back. It was the best thing ever to see my family,” Fifita told AAP.
“My wife and I were only husband and wife for a day before I came over here and them coming here has been the best thing for me mentally.
“It was killing me mentally that I didn’t have any family here, just my brothers in the team.”
Fifita kept in regular contact with his family over the internet but he felt like he was making up for lost time when he could hold his son in his arms again.
“The baby’s grown up so much since I left him at home, even in four or five weeks,” Fifita said.
“He’s walking now and he’s so big … it feels like I’ve missed out on so much.
“But now being able to go back to see them in the apartment every day, it feels like I’m at home.”
Fifita says his stable home life and becoming a father are behind his incredible achievements with club, state and country in 2013.
The NSW forward has played in all of Australia’s four matches at the World Cup and his impact off the bench continues to be crucial in the Kangaroos’ bid for glory.
Fifita expects the lift gained from his family’s arrival will help him make an even greater mark on the field against Fiji.
“I play a lot better when I’m happier so, hopefully, I can go out there and do my job knowing that my family are there,” he said.
“It’s a privilege every single time I run out on the field and play in front of them because they know they are the only thing I play for.
“Without them, I don’t think I would have got this far ever.”