Ryan Jones, an ex-Wales rugby captain, said that "I feel like my world is falling apart", following the reveal of his diagnosis of a serious brain injury.
He becomes with this reveal the latest high-profile former rugby player to have been diagnosed with a serious brain injury.
Jones, a back-rower who won 75 caps for Wales and a further three for the British and Irish Lions, said he was told in December he was suffering from early onset dementia, probable chronic traumatic encephalopathy (CTE).
"I feel like my world is falling apart," the 41-year-old told the Sunday Times.
"And I am really scared. Because I've got three children and three step-children and I want to be a fantastic dad.
"I lived 15 years of my life like a superhero and I'm not. I don't know what the future holds... I'm not able to perform like I could.
"And I just want to lead a happy, healthy, normal life. I feel that's been taken away and there's nothing I can do. I can't train harder, I can't play the referee, I don't know what the rules of the game are any more."
How rugby deals with the issue of head injuries and concussion has become a major talking point within the game.
A number of ex-players, including England World Cup winner Steve Thompson and Jones' former Test team-mate Alix Popham, are part of a legal case against World Rugby, the Rugby Football Union and the Welsh Rugby Union over an alleged failure to protect them from concussion risks.
"It is (rugby) walking headlong with its eyes closed into a catastrophic situation," he said.
Last month, World Rugby announced, in some cases, elite players will face an increased minimum period of 12 days on the sidelines under toughened concussion protocols.
The previous system meant a player who failed a head injury assessment could conceivably feature again the following weekend, provided they followed and passed return-to-play protocols.
But concerns that eve then new procedures were inadequate surfaced when Ireland captain Johnny Sexton was passed fit to play in the second Test against New Zealand.
The fly-half suffered a head knock on the half-hour mark in the first of a three-match series.
Sexton failed a sideline Head Injury Assessment during Ireland's defeat in Auckland but passed the second and third stages of the HIA process before leading Ireland to a memorable 2-1 series triumph over the All Blacks.
Jones's partner Charlie, said his memory lapses meant talking to him was at times "like having a conversation with my 85-year-old grandad".
And Jones, who retired in 2015, said his experience had made him wary of encouraging his children to have a career in top-flight rugby.
"Do I want to be a father in ten years, or if Charlie is left to pick up the pieces, having a conversation with my son when he's 30, going, 'Guess what, you've trodden the same path as your dad'?," he said.
"We knew all along and we didn't stop you and boy do we wish we had. I couldn't live with that."
