Lively, who was shooting her own film "The Shallows" at the time, was a calming influence.
"Blake helped me through that," Reynolds said. "I'm lucky to have her around just to keep me sane."
Reynolds was diagnosed with anxiety after he completed filming on "Deadpool," he told GQ in November.
"When it finally ended, I had a little bit of a nervous breakdown. I literally had the shakes," he said. "I went to go see a doctor because I felt like I was suffering from a neurological problem or something. And every doctor I saw said, 'You have anxiety.'"
It wasn't the actor's first bout with anxiety either, he told Variety.
"I have three older brothers. Our father was tough. He wasn’t easy on anyone. And he wasn’t easy on himself," said Reynolds, who grew up in Vancouver, Canada. "I think the anxiety might have started there, trying to find ways to control others by trying to control myself. At the time, I never recognized that. I was just a twitchy kid."
Now, Reynolds is trying to take in all the attention he's received from "Deadpool" -- including last month's Critics' Choice Awards.
It took Reynolds 11 years to get the movie made. But he said he still has a hard time believing that it has become the highest grossing R-rated film and the first live-action comic book film to receive a Globe nomination.
"I think there’s a slight sadness to it," he told Variety. "I haven’t really been able to come to terms with it. It’s really proof that literally anything can happen in Hollywood."