Jack Noseworthy goes inside the troubled mind of Marilyn Monroe as her therapist Alan DeShields in the new Lifetime miniseries "The Secret Life of Marilyn Monroe."

Noseworthy plays the only fictional character in the biopic, based on the biography by J. Randy Taraborrelli, that pulls back the layers on Monroe's (Kelli Garner) relationship with her mentally ill mother (Susan Sarandon) and the struggle to keep her public image separate from her private life.

"All the men in her life were father figures. She was always looking for her father so the device in the film was they wanted a contemporary male figure to be talking to her. So they created my character," Noseworthy tells Headlines & Global News in an exclusive interview.

Monroe invites Dr. DeShields to her home in Brentwood to evaluate him as a possible therapist, a routine she carried out often, interviewing potential doctors and therapists in search of a new therapy strategy to figure out her emotional state.

"Marilyn had a doctor file. She had so many doctors and therapists and she was an incredibly smart girl. So she was always interviewing these therapists and trying to find a new type of therapy to get into," Noseworthy says. "It was an addiction. It really was another addiction for her."

The iconic movie star suffered from multiple vices, including alcohol and prescription drugs, but she still managed to carry on a lifestyle and career as a powerful woman in Hollywood. Noseworthy quickly pointed out that Monroe made the decision to leave her husbands, which were James Dougherty, Joe DiMaggio and Arthur Miller, an action most women at the time would never have taken.

"She was a strong woman who wasn't afraid to take care of her life or step into an area that maybe at the time people would be like, 'Oh, I could never leave my husband,'" the 50-year-old actor says. "Marilyn was like, 'No! You know what? You're not the man for me. This isn't working. This is over.'"

Noseworthy shared all his scenes with Garner as Monroe. The two filmed their scenes in sequence as the long therapy session unfolds and the actress reveals her life from a small child to the height of her career.

"I had the pleasure of seeing [Garner] reveal Marilyn for the first time which was so beneficial and wonderful because I was seeing her for the first time just as my character was seeing Marilyn Monroe for the first time," he says. "It gave so much authenticity to the emotions because as we went along, we were finding it together, just as if it had happened in real life."

Garner's screen partner commended her performance and the difficult task she had to play a real-life character that's been portrayed on screen so many times in the past.

"It's not easy to develop something in a new way and get people to think differently about someone that they think they already know," Noseworthy says. "It's not easy to portray a living person, too. You feel responsible to be respectful to them."

The "Killing Kennedy" star understands that responsibility when he played Robert Kennedy in the TV movie starring Rob Lowe as John F. Kennedy, based on the book by Bill O'Reilly. From his research for that role, he already had a greater sense of who Monroe really was beyond what the public saw on screen and in the tabloids.

"You're reading about the time period and somehow it was in my social subconscious, I was aware of Marilyn. I was familiar with some of these major instances in her life. Some I didn't," Noseworthy says. "Nobody really knows the intimate details of what happened behind close doors. There's such an urban legend around her. They thought she was this dumb blonde. I never got that. She's a big movie star that could act."

"The Secret Life of Marilyn Monroe" will delve more into the life Monroe shared with her mother Gladys, who spent most of her adult life in mental institutions. Unlike Garner's Monroe, Sarandon plays a real-life woman that is not as well known to the public.

"In some ways, Susan had almost carte blanche because she was creating a character of someone we don't have images of or an understanding of," Noseworthy says. "It was a joy to watch an actress of that level, with that skill, be given an opportunity to play a really interesting woman that we don't know."

As a young child, Monroe would either stay with her Aunt Grace (Emily Watson) or be forced to live in an orphanage while her mother sought treatment or skipped town with another man.

"Her aunt had her own family and husband. When times were tough, they had to put Marilyn in the orphanage just to take care of her because they were going through the [Great] Depression," Noseworthy explains. "When they had some money, they would take her out. She would live with the family for a little while and then they'd put her back in. It was a very rough childhood."

Beyond the performances, Noseworthy praises the crew for creating a beautifully shot series that "gelled really well" with the actors on-screen. Everyone from director Laurie Collyer and her cinematographer Chris Manley down to the costume designers and make up artists maintained the same "head space"

"It seemed like everyone had the same artistic ambition," he says. "I'm so proud of all the departments and how they worked together and created this movie because they succeed. We succeeded."

And for those of you who still think they know everything about Marilyn Monroe and don't need to watch a new series on the legendary actress, Noseworthy has just one thing to say:

"You don't know Marilyn the way you think you know Marilyn."

"The Secret Life of Marilyn Monroe" starts tonight, May 30 at 8 p.m. and continues tomorrow for part two at 8 p.m. on Lifetime.