Actor Jeremy Piven, who pulled out of David Mamet’s Broadway play “Speed-the-Plow” citing mercury poisoning late last month, finally spoke out about being sick.

After attending Sunday night’s Golden Globe Awards, Piven, who lost to Tom Wilkinson in the supporting category, celebrated with fellow actors at one of the many after parties. 

“I was so sick for most of the run of the show,” he was quoted by Fox News as saying.

“Some days I would sleep right until the time I had to go to the theater. I didn’t know what was wrong with me. I was exhausted,” he added.

According to reports, all that mercury in the actor's system was due to Piven's diet, which is rich in fish. Piven, who regularly eats sushi twice a day for years, has also taken certain Chinese herbs that, along with the sushi, could have led to elevated mercury levels. He experienced the first symptoms back in October when Piven reportedly told the show's producers that he was worried he might be suffering from mononucleosis (the kissing disease) and the Epstein-Barr virus.

“Finally, I went to a doctor at Greenwich Hospital in Connecticut just so it wouldn’t turn into a circus. He said, 'you’ve got to stop working.' My heart rate was 47. My mercury level was off the charts. I hadn’t had a real break in 20 years of acting,' Piven explained.

The 43-year-old actor, who is famous for his Emmy and Golden Globe-winning turn as the rapacious, unscrupulous super-agent Ari Gold in HBO’s “Entourage,” opened to fantastic reviews as superproducer Bobby Gould in Mamet's “Speed-the-Plow.”

Just days ago, there were reports that the producers of the play Piven starred in threatened to sue the actor for trying to get out of his contract. It turns out they didn’t have insurance on Piven. If they had, their insurance company would almost certainly investigate the actor’s claim before paying out any money. When Piven quit the show, “Speed-the-Plow” was a week away from returning its $3.5 million investment.

Piven, who was scheduled to perform throughout the show's run, which is scheduled to run until Feb. 22nd, added that he felt much better now and was humbled by the entire experience, insisting he solely followed a doctor’s advice to withdraw from the play.