In an appearance on "The Late Show With David Letterman," Helberg revealed he ended his relationship with now-wife Jocelyn Towne when he realized he wanted to marry her.
The two are working on a film together inspired by his story.
"It's sort of embarrassing. [The movie is] about my wife and I and our break up before I proposed. I thought I would like to marry this girl, so first of all I'm going to systematically destroy my entire life and our relationship and lie and ruin all my friendships," Helberg said.
"I freaked out, I thought I had feelings for other people, I thought that I needed more of an exciting life. I had the perfect thing but for whatever reason … .
"It was an exercise in self destruction," he said.
Helberg said that after they broke up, Towne, an actress and producer, moved to Paris and ended up with another man. Helberg followed after her and they eventually ended up together.
"I proposed immediately on her return because I thought if I can just trap her and force her to marry me that's the most romantic thing anyone could ask for," Helberg said.
Take a look at the interview: