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.
The couple are expecting their second child together.