Olivia Lua, a 24-year-old doe-eyed brunette from Philadelphia, was an instant hit when she joined the LA porn scene in 2016.

She shot dozens of scenes for hard-core movies like “Helpless Teens” before being handed a lucrative contract in April 2017 with porn producer LA Direct Models.

Lua — who also went by Olivia Voltaire — described herself as an “exhibitionist” and posted graphic images of herself having sex on social media.

She thrived in her new career, and was nominated last year for Best New Actress at the Adult Video News Awards.

It was when the cameras were off that she fell apart.

“Unlovable,” she wrote on Twitter Jan. 13, three months after LA Direct Models canceled her contract. They later said she had been showing up to work high.

On Jan. 18 — the day before she was found dead of a suspected overdose of drugs and alcohol — she tweeted a picture of herself with the caption: “I feel it everywhere. Nothing scares me anymore.”

Lua was the fifth porn star to die in seven months, with industry officials attributing the tragedies to either suicide or overdoses.

The statistic is shocking, insiders say — but the root of the problem is not. Like the underemployed and unemployed across America, the young women struggled with a lack of steady work.

There are now more porn actors than ever, thanks to increasing platforms, as well as growing mainstream acceptance. That makes the competition fierce.

Meanwhile, the pay hasn’t gone up in years. To make any kind of decent money, porn performers have to work a lot — or do super kinky scenes.

Ela Darling, an eight-year veteran of the porn industry and past president of the Adult Performer Advocacy Committee, said actresses are paid between $500 to $700 to have sex with another girl and up to $1,000 to get down with a guy.

But the rate can double or triple if a performer is willing to have multiple partners or participate in anal sex or “anything extreme,” she said.

She said the money hasn’t increased, partly because studios say they’re making less profit now, since content is often pirated by streaming sites that show it for free. There also are the “outliers who are happy to accept lower rates,’’ Darling said.

Still, she said, high-demand performers can routinely pull in six-figure salaries because they have enough clout to negotiate ownership rights and can rebroadcast footage elsewhere.

“When the camera is on, everybody is happy,” said behavioral scientist Gad Saad, a chair at the John Molson School of Business in Montreal, who studies the porn industry.

“The problem is that the work dries up. The phone stops ringing, and they say, ‘Now what?’ Porn stars aren’t the best at making a ‘what if’ plan for their future.”

He insisted that people who enter porn are no more prone to mental issues than anyone else.

In 2012, “the widest study ever conducted . . . showed porn stars did not come from a background of sexual abuse and, in fact, had higher esteem than the normal population,” Saad said.

Darling, 31, agreed.

“Porn is a fine job,” she said. “What’s tough is that it’s freelance. What’s tough is the down periods when you’re alone with yourself, thinking, ‘Will I ever work again?’ ”

Darling said the “feast-or-famine” business — new recruits are often in demand until they’re not — is part of the reason her best friend, January Seraph, killed herself.

Seraph, who hanged herself July 22 in her San Francisco apartment, is considered the first in the rash of deaths.

Seraph, 31, was a star of more than 50 videos with titles such as “Digital Sin” and “Leather Dominance.”

But Darling said Seraph, whom she described as “the sweetest person in the world,” struggled with the lulls and often discussed what to do when producers stopped calling.

“It’s not like you can stop being a porn star and be a teacher. And not being busy can lead to bad things,” Darling said.

APAC President Mia Lia, a veteran sex performer, called the rash of deaths a troubling pattern.

“One death is a lot to deal with, but five? That’s just unheard of,” she said. “We are collectively rattled.”

Yuri Luv was one considered a rock-star veteran of the porn industry. Born Yurizan Beltran in Los Angeles, the buxom brunette worked for eight years and was nominated for several awards, including an XBIZ for “Best Scene — All Girls” for 2014’s “Lesbians Unchained.”

She was featured in 28 movies in 2012 and 22 in 2013, but in 2016, she appeared in just three.

On Dec. 13, Luv’s body was found in her Bellflower, Calif., apartment by her landlord. She was 31.

Nickey Milo, a fellow performer, said pills were found near her bed.

Performer Carmen Valentina told The Post that porn is a rough business to age in.

Valentina, who started her own sex webcam business because she didn’t want to rely on outside producers, is also 31 and constantly struggling to remain relevant.

“When you first get in, everybody loves you, but there are always new girls coming in, and it’s easy to feel discarded. You really have to have your head on straight to get through it,” she said.

Valentina said porn is no different than being a regular movie star where you rely on image — and feel crushed if you don’t get called.

“It’s a career where you have to rely on your looks. When you’re young and pretty, you think it’s going to last forever, but when it doesn’t, that’s when you have to tap your inner strength.”

Like Luv, Adult Hall of Famer Shyla Stylez saw the work dry up as she got older.

Stylez, from Vancouver, moved to the so-called Porn Valley in California after high school to become an adult-film star. She appeared in more than 400 films, including “Perverted Point of View,” before calling it quits in 2016 and going home.

She passed away on Nov. 9 at age 31. Her family would not reveal the specifics.

Fellow adult film star Alana Evans called Stylez a tragic film goddess, like Marilyn Monroe.

She tweeted, “At a loss for words. So sad that my old friend @MsShylaStylez has left us. You were one of the most beautiful woman I’ve ever known.”

August Ames, 23, said on Dec. 3 that she had been “replaced” for a LA Direct films scene the week before, tweeting out what seemed to be a sour-grapes message.

“Whichever (lady) performer is replacing me tomorrow for @EroticaXNews, you’re shooting with a guy who has shot gay porn, just to let cha know,” she wrote.

Ames suddenly found herself being trolled by bullies who accused her of being anti-gay. The Nova Scotia native committed suicide Dec. 6 in her Los Angeles apartment.

Porn queen Jenna Jameson, 43, called Ames’ death “disappointing and tragic.”

“The scariest part of the attacks on @AugustAmesxxx is that they were led by quite a few big females in the adult industry. These women fanned the flames of the trolling against August,” she tweeted.

APAC’s Lia said she had worked with Ames and thought she was “super sweet.” But she added it’s hard for performers to switch to private mode when dealing with family and friends — or social media’s judgment.

“It’s exhausting,” she said.

To compound matters, Lia said many sex workers do not have health insurance and can’t afford to pay for therapy. She and her colleagues have begun distributing a list of affordable “sex positive” mental-health workers as a result.

Saad said the one thing that might help stars is an exit strategy.

“According to the data . . . they’re happy when they get there,” he said. “But when my star starts to dwindle and my body has been used 33,000 times, what do I do? What’s going to happen? They don’t seem to think about that.”