Jockey Frankie Dettori fears he may never repair the damage done to his reputation by a failed drugs test which has seen him handed a six-month ban.
The Italian racing legend, 41, will not return to the racecourse until a fortnight before next year's Derby, with his suspension, handed out yesterday by French racing authorities, running until May 19.
One of the biggest names in world racing, Dettori tested positive for a banned substance, believed to be cocaine, at a meeting at Longchamp in Paris in September.
It is alleged that officials were "tipped off" that he had been taking drugs, the Daily Star said, and that Dettori's legal team said the failed drugs test was not for a performance-enhancing substance.
The three-time British champion jockey said the indiscretion came as he feared for his future, having slipped down racing's pecking order.
"I'm ashamed and embarrassed," Dettori told the Star. "It was one night of madness with friends.
"I dropped my guard when I was at my weakest. I was in a dark place. I was very low, my job was going down the drain.
"When I woke up the next morning I regretted it but it was already too late. I will regret it for the rest of my life."
Dettori's suspension was backdated, as he had already been prevented from riding in France since November 20 when medical tests were first passed on to a disciplinary panel at French racing authority France Galop.
The jockey has since been coming to terms with what he did.
"I've been in hiding since it happened because of the shame factor," Dettori said. "It's not very pleasant.
"People will always remember it. Now when they look at me they won't think of the things I have done for racing in the past 20 years, they'll just think, 'He's the guy who got caught with drugs'.
"But you can't change the past and you've just got to move on."
He played down any suggestion the ban could signal the end of his career, and plans to operate as a freelance in 2013.
"I have still got a good five years left in me," he said.
Jurisdictions worldwide, such as the British Horseracing Authority, are expected to reciprocate the terms of the suspension, and Dettori's next important date is when he will be summoned to the headquarters of France Galop to be retested towards the end of April.
Dettori, who was cautioned by police for possession of cocaine in 1993, made the headlines in October when his 18-year association with powerful owners Godolphin came to an end.