But his exploration was brought to a halt when at 19 he was raped by a male crush Conley calls David who then outed him to his shocked parents.
"David had trumped me. The knowledge of my homosexuality would seem more shocking than the knowledge of my rape; or, worse, it would seem as though one act had inevitably followed the other, as though I'd had it coming to me," Conley writes in Boy Erased.
His parents gave him an ultimatum; attend gay conversion therapy or never see his family again.
Believing his attraction to men was sinful and afraid of eternal damnation, Conley enrolled in the controversial Love in Action facility in Tennessee.
"I was in free fall from being raped, and having the rapist say he had also raped a 14-year-old boy," Conley told BBC News.
"And then my dad gave me the ultimatum. I was terrified of losing God. I prayed every night."
When Conley attended the residential conversion therapy program in 2004 it was run by 'ex-gay' executive director, John Smid, who abandoned the group in 2008 and is now married to a man.
For two weeks, Conley was told his homosexuality was wrong and subjected to questionable group therapies such as taking part in a mock funeral for a gay man who had died of Aids.
After he completed the 12 step residential program, Conley had six months of private therapy sessions which left him suicidal before his parents took him out of treatment.
Despite the harrowing experience, Conley doesn't blame his parents for the trauma and treats them kindly in his memoir, arguing they had put their trust in the wrong people.
"They had no idea what was going on," Conley told BBC News. "My mum had started asking questions at the end, and that's when they'd taken me out of the program. We weren't meant to talk about what happened in there.
"Yes, my parents made a terrible mistake which could have cost me my life. But they didn't know what they were doing to me."
After leaving Love In Action's program, Conley went back to university to study queer theory and published Boy Erased in 2016.
He now lives in New York with his husband and has just finished a novel about a gay historical romance.
In 2017 it was announced Edgerton had picked up the project and Lady Bird star Lucas Hedges would star as Conley.
But the decision to have not to have a queer actor play a gay character sparked controversy, with Conley defending the casting choice in a blog post.
"Let me be clear: As of this moment, my story is not being 'straightwashed.' This is my story, and I have been involved in every step of the process," he wrote.
Meanwhile, Crowe took his role playing Conley's father very seriously, even flying to Arkansas to attend one of his dad's services last year.
"It made a little bit of a scene — it's a very small town, a lot of people have been on meth," Conley told The Guardian.
"And then Russell Crowe comes in with his entourage and sits down. I was told my dad paused in his sermon for about two minutes, before continuing."
