Jim Parsons became emotional as he revealed why he was ready to quit “The Big Bang Theory” last year.

The program, which premiered in 2007 and lasted twelve seasons, concluded last year.

During a conversation on “David Tennant Does a Podcast With …”, the 47-year-old actor, who played Sheldon Cooper on the CBS comedy, sobbed when speaking up about his decision to leave the show after 12 seasons.

While Parsons acknowledged to have “suspicion in my heart” that his two-year contract on the comedy for seasons 11 and 12 would be his final, the concept didn’t become a reality until the penultimate season shot its final episode.

Along with playing the humorous and intelligent scientist on the award-winning sitcom, Parsons flew to New York in 2018 to act on Broadway and commit to commercial shoots in what he calls “an intense summer.”

“It was a complicated road, as you can imagine,” he remarked. “We went through the 11th season, and then that summer, I went to New York to do ‘Boys in the Band’ on Broadway, and I think anything I felt got really affirmed.”

He didn’t get to relax that first week, despite the fact that his day off fell on Sundays.

“On that Sunday that I had my first day off, I shot a commercial,” he recounted. “I had a contract with Intel and so I scheduled that. I was exhausted.”

In addition to his hectic work schedule, Parsons was heartbroken about the condition of his 14-year-old dog, which he shared with his partner Todd Spiewak.

“I was exhausted, and I was really upset about one of our dogs was getting really at the end of his life around then,” he explained. “I’ll never forget that walk around the park to let him go to the bathroom before we went for the commercial shoot. He just looked so bad, and I was so tired, and (my husband) Todd was like … ‘we gotta go, we’ve scheduled this, they’ve fit everything around your schedule.’ And I just started crying.”

“It makes me upset now. I was like, ‘This dog’s gonna die while I’m off working. I feel so bad,'” he continued.

“So I went and did the commercial, I came back, and then Monday I went to do the play and he had a really bad seizure that night, so I knew that we had to make a decision… We called somebody and the person comes to put the dog to sleep at home,” he continued. “So that happened Tuesday. It really upset me. Still does.”

Jim Parsons with the cast of The Big Bang Theory with Ellen DeGeneres | CREDIT: MICHAEL ROZMAN/WARNER BROS.

Before his next day off, Parsons knew he had to go through six more Broadway shows. “I kept thinking, ‘I don’t know how I’m going to get to the end of this performance.’ I was just so beaten down,” he said. “But I did.”

He then described how he fractured his foot in an on-stage mishap a few days after the dog was put down, stating, “It was the scariest moment for the next couple of days because I felt like I was at the edge of a cliff. I was teetering and I saw something really dark below between the death of the dog.”

“The bottom line was that it was a really intense summer. The dog passing away, he was 14, and Todd and I had been together for 15 years at that point, so it just was the end of an era.”

He concluded: “I had this moment of clarity that I think you’re very fortunate to get in a lot of ways, of going ‘Don’t keep speeding by’. You know? ‘Use this time to take a look around.’ And I did.”

In addition, when he reflected on his late father, Parsons was forced to face the ephemeral aspect of life.

“My dad had passed years before, but he was 52. And I realized that at the end of season 12 I would be 46,” he said. “… It was just a context thing.”

When he returned to Los Angeles, Parsons informed creator Chuck Lorre and writer Steve Molaro that the show’s 12th season would be his final.

“I said, ‘If you told me that like my father I had six years left to live, I think there’s other things I need to try and do. I don’t know what they are, but I can tell that I need to try,'” said Parsons.

As Parsons became emotional while discussing his exit from the program, he took a minute to thank his cast members, adding that working with them for over a decade has been “a complete joy”