The 23-year-old Italian defeated Taylor Fritz in straight sets to win his second Grand Slam title to add to his first in Australia in January.
However, his path to victory was accompanied by questions over the affair which saw him twice test positive for banned substance clostebol in March.
He escaped a lengthy ban when the International Tennis Integrity Agency (ITIA) found he was not guilty of wrongdoing after he had been inadvertently contaminated by his physio.
The Italian sacked physio Giacomo Naldi and trainer Umberto Ferrara, citing a loss of confidence in them.
The decision to clear the Italian was met with scepticism by some players in the locker room who suggested that Sinner had benefitted from preferential treatment due to his status in the sport.
"It was and it's still on my mind. It's not that it's gone, but when I'm on court, I try to focus about the game, I try to handle the situation the best possible way, communication with the team, in the practice courts," said the world number one.
"It was not easy, that's for sure, but I tried to stay focused, with which I guess I've done a great job."
Sinner admitted that the case had cast a cloud over him but he believes that fans and most players have been supportive.
"Obviously it was very difficult for me to enjoy in certain moments," he added.
"Also how I behaved or how I walked on the court in certain tournaments before, it was not the same as I used to be, so whoever knows me better, they know that something was wrong.
"But during this tournament, slowly I restarted to feel a little bit more how I am as a person. Doesn't really matter how or what the result was. So this tournament, for sure, helped me a little bit."
Despite the controversy, Sinner is enjoying a stellar season.
He has captured six titles, racking up 55 wins against just five losses.
His triumph on Sunday allowed him become the first man since Guillermo Vilas in 1977 to win his first two Grand Slam titles in the same season.
Sinner believes that Sunday's win in New York has more impact for him than his Australian Open breakthrough.
"Melbourne was a kind of a relief because you never know if you can win one Grand Slam or not, but when you win one, you know that you can do it," he said.
"Here it was difficult because also the pre-tournament circumstances weren't easy. I felt like that I have grown match by match and that my confidence level went higher and higher at some point.
"It was different because I had more pressure this time than in Australia. I'm happy how I handled this one. Yeah, I'm just excited to have this trophy with me."
