Titi Branch had it all — a multimillion-dollar hair-care empire she built up from a humble Brooklyn salon, a loving sister who was her business partner and confidante, and a boyfriend with whom she dreamed of starting a family.

Yet three weeks before Christmas, she fell into a depression so deep, she would not escape it. The beautiful entrepreneur hanged herself in her Midtown apartment on Dec. 4, authorities say.

What led her to such a dark place, and who might profit from her tragic death, are questions now at the center of a court battle between the two people closest to her: sister Miko Branch, with whom she launched “Miss Jessie’s” hair products, named after their grandmother, and Anthony Spadafora, the Pennsylvania man she loved. Each blames the other for the Queens ­native’s downward spiral.

Titi, 45, was under Spadafora’s Svengali-like spell, Miko claims in Manhattan Supreme Court papers, saying he isolated her from her family, manipulated her and treated her like a human ATM.

Titi even changed the beneficiary of her $2 million in life insurance policies from her sister to Spadafora — because of his “undue influence,” Miko claims.

“My sister’s death has been a devastating blow,” she told The Post. “It was only after Titi’s death that we learned more about what she’d been going through and how her affairs were being managed.”

Spadafora “wielded exceptional control over [her] while fully aware that her mental health was severely compromised,” the sister claims, referring to Titi’s “disabling” depression.

In just two years Spadafora, 43, managed to “extract” hundreds of thousands of dollars from Titi to launch his own beard-care business, Maestro’s Classics; $420,000 to buy and renovate a Pennsylvania house; and a $135,000 interest-free loan.

“In exchange, [she] received nothing,” Miko charged.

Titi was ready to kick Spadafora to the curb last year when she found out he sexually propositioned her trainer, but he knew how to keep her in line, Miko alleges in court papers.

Spadafora “took extreme measures to stop her . . . sending compromising photographs that he had taken of her,” the sister claims.

Within days of her death, he peppered her grieving parents with emails claiming he had a new will drafted by Titi giving him 50 percent of everything, according to the suit.

He also took his girlfriend’s computer and refused to return it to her family members unless they forked over Titi’s expensive Cartier bracelet, according to court papers.

When they did, the computer he returned had its drive scrubbed clean, the Branch family claims.

Spadafora called the charges “ridiculous.”

He claims Titi’s bitter falling out with Miko in September 2013 prompted her to change the beneficiary on her life insurance policy, and drove Titi out of the company she and Miko started together in 2004.

“She was changing ­everything,” he said.

The sisters “loved each other” but had different management styles, and as tensions grew, Titi couldn’t take the stress, he claims, calling Miko “the bully of Brooklyn.”

“They’re trying to paint me as a villain,” he said.

He met Titi on Match.com in 2012, and the relationship quickly became serious.

“It was a real love . . . I was dedicated to her; she was dedicated to me,” he said, calling Titi his “Lady Liberty.”

The pair traveled to Italy and France, shared homes in New York and Pennsylvania, and wanted to have children, but multiple rounds of in-vitro fertilization failed, leaving Titi drained and despondent, her boyfriend told The Post.

In December, Spadafora got a call at his Pennsylvania home from a friend concerned about Titi’s absence. Spadafora rushed to her Manhattan apartment. Police were already there.

“My love failed. I thought it was good enough if there wasn’t a baby,” he said, weeping.

Spadafora says he wants to make peace with the family. “I don’t want to see this turn into a war,” he said.