Utah native Joshua Holt's anguish ended when he was freed last month from a Venezuelan prison after nearly two years held without trial.

But the nightmarish scenario he endured still haunts him.

In an exclusive interview Tuesday on "Today," Holt, 26, recounted the poor conditions inside El Helicoide, or The Helix — a prison in Caracas criticized for its human rights abuses. He said cockroaches crawled over him inside his tiny cell, which was about the size of a twin-sized bed, and a plastic bag was used to cover the door. He sat in his underwear, barely about to breathe.

"They never took me out to go to the bathroom," Holt added. "If you had to use the bathroom, you either had a bottle or a newspaper."

Holt, a Mormon missionary, was in the South American country to marry a Venezuelan woman, Thamara Candelo, whom he met online. The couple was planning to move to the U.S. with Candelo's two young daughters.

But their future was upended when an anti-gang police squad accused the couple of stockpiling an AK-47 assault rifle and grenades at her family's home.

Holt was incarcerated in June 2016. The State Department later called the weapons charges "questionable."

"At first, I wasn't as afraid because here in America you trust your police officers," Holt said. "Over there, I didn't know it was so dangerous."

Police investigators, he said, tried to pit Candelo against her new husband. They put her fingers in pencil sharpeners, and they threatened to tase her, according to Holt.

Meanwhile, Holt's mother worked tirelessly to get the interest of American politicians.

"There was a lot of anger, but I had to keep pushing," Laurie Holt said on "Today" with her family beside her. "I knew that I was his voice."

It wasn't until last month when Holt's case gained renewed attention: A prison riot broke out at El Helicoide, and Holt managed to post two short videos to his Facebook page from inside the facility saying he feared for his life.

Behind the scenes, Utah politicians Rep. Mia Love and Sen. Orrin Hatch, as well as Sen. Bob Corker, R-Tenn., and others, helped to negotiate his release. A week later, he was freed. He returned to the United States and met President Donald Trump at the White House.

With his life in America restored, Holt said on "Today" that he's writing a book with his wife and they want to highlight the difficulties people in his position face.

"Through that book and through talking to people, we're hoping to help bless people," he added.