After his older brother, Omar, died suddenly in 2008, Sagna struggled for almost a year, his performances on the pitch suffered and critics started to doubt his ability.
The 27-year-old Arsenal defender recovered to become France's undisputed number one right-back and is now looking forward to playing the first World Cup to be staged in Africa, where his Senegalese parents were born.
"I went through a very dark period for a year, it was really not easy, but now I'm here, feeling well," Sagna told reporters at France's training camp for the June 11-July 11 finals in South Africa.
"It was as if I had a burden weighing over my head," he said of his difficult period. "I was not feeling well, I was not feeling myself and that affected my performances."
"To be open about it helped me a lot," he said.
Sagna, who became Domenech's preferred option at right back after Willy Sagnol retired in the wake of France's Euro 2008 flop, said he believed France could bounce back from a string of dismal performances.
"The answer must come from us, the players," said Sagna, whose signature gold braids have their origins in a bet he made with his father when he was a child.
"The coach and the staff are there to help but it's up to us to work hard to go all the way."
"We were rubbish against Ireland and Spain, that's true," he said.
"We have weaknesses, we realise that, but we also have strengths. I understand the supporters and I don't believe they don't love us any more. We want to win for ourselves but also for them."
