Sept. 11 widow Kathy Trant has turned her Long Island home into a $2 million showcase, traveled from the Vatican to Las Vegas, blown $500,000 on shoes, and bought breast jobs for pals and even strangers.

In the 3½ years since her husband, Dan, died in the World Trade Center attacks, she has burned through nearly all the more than $5 million she received in compensation and donations. She says she treated the millions “like Monopoly money.”

The mother of three has become a self-described “shopoholic” – and her compulsive buying has left her with intense guilt, shame and sadness.

After the plane hit the north tower on Sept. 11, Dan called Kathy from the 104th floor, where the 40-year-old worked as a bond trader for Cantor Fitzgerald. He said the smoke was unbearable. “I love you, and I love the kids,” were his last words. His remains were never found.

Following the funeral, Kathy’s weight zigzagged from 90 pounds to 170 pounds and down again. She numbed herself with booze and antidepressants.

Then she began spending.

With a seemingly bottomless bank account, she threw herself into expanding and renovating her 1,800-square-foot Northport, L.I., home, a project she and Dan, her “soul mate” of 15 years, had discussed doing together.

She didn’t stop until she nearly tripled the square footage, and spared no expense in decorating and furnishing her dream house.

“That’s what kept me alive,” she said. “Staying up late ordering chandeliers from catalogs.”

She spent $350,000 installing a full basketball court, also equipped for volleyball, tennis and Rollerblading, and a heated pool and hot tub in the back yard.

The kitchen has white marble countertops lined with gleaming appliances she rarely uses. The floors are rich Brazilian walnut.

A red-white-and-blue den, which includes a shrine of Dan’s mementos, features four Peter Max paintings of the Statue of Liberty, which ran her $15,000. There are seven flat-screen TVs around the house. In the finished basement stands a $20,000 cherry-wood pool table.

The walls are decorated with sports memorabilia, including a Boston Celtics ball autographed by players on the team that once drafted her husband, who played professionally in Ireland.

In her master bedroom, she added a glass-enclosed fireplace that also serves the bathroom, with its claw-foot tub.

With the house makeover done, she really started to splurge.

Opening her walk-in closet, Trant said, “This is my addiction.”

A floor-to-ceiling shoe rack is filled with $400 to $1,200 pairs: Prada, Marc Jacobs, Manolo Blahnik, Jimmy Choo, Emilio Pucci, Vera Wang. Handbags include Fendi and Judith Leiber, designs priced at $5,000 each. The gowns have labels like Versace, Christian Dior and Roberto Cavalli – each costing her thousands.

“It’s disgusting. I’m ashamed of it,” she said, adding she hopes that telling her story will help others with the same problem.

“This is my misery. This does not make me happy. When I come home with it, I have guilt, horrible guilt. You know how many starving people I could feed with all these shoes?”

She wears 10 percent of the clothes, she said, and gives armloads away to friends. But she keeps buying more.

“I feel if I look pretty, I’m going to find someone like Danny,” she said. “I want him to come home.”

Trant’s pet Yorkie, Mollie, cost $3,500; her daughter has three others. She paid $60,000 cash for a Chevy Tahoe SUV, and also bought a BMW.

She has traveled to Italy, Jamaica, Asia and Europe; taken friends and relatives on four Caribbean cruises for $50,000; taken 20 to the Bahamas for $30,000; 10 to Las Vegas for $15,000; and six to the Super Bowl for $70,000. The last couple of summers, she’s paid $13,000 to rent a 10-room North Carolina beach house for a week for her kids and all their pals.

Trant has showered those around her with obsessive generosity.

She gave one friend $20,000 to pay her bills. She gave her former housecleaner $15,000 to buy a home in El Salvador. She’s sent $1,000 checks to a friendly clerk in Bergdorf Goodman, and treated salesgirls at Saks to shoes.

After getting a facial in Las Vegas, she gave the beautician, a single mom, $4,000 for breast implants. She gave a friend $7,000 for a boob job because, Trant said, the woman “hated her breasts and didn’t want to spend her son’s college tuition money.”

She buys wrinkle-reducing Botox injections for girlfriends. A plastic surgeon gives her a discount – $600 for three at a time. Trant tattooed an American flag and “9/11” on her back and got a permanent black stripe of “eyeliner” tattooed on her eyelids, which never runs when she cries.

She gave one friend a $3,000 watch. “She didn’t take it, and I just threw it at her,” Trant said.

“My friends say, ‘Stop, Kathy, you’ve got to stop.'”

Soon after her husband was killed, Trant said, some $3 million in donations flowed in from his admirers and fund-raisers. Dan was beloved as an athlete and coach of youth soccer and basketball teams.

Then, in 2003, the federal Victim Compensation Fund awarded the Trants more than $4.2 million.

The sum was based, in part, on Dan’s future earning potential. Before 9/11, the family had lived modestly, but his career at Cantor was skyrocketing. He earned about $130,000 his last year, plus tens of thousands in bonuses.

Kathy, who got half the government payout as her share, gave $100,000 to her mother-in-law, who wasn’t legally entitled to any money. The other half was split among her three kids – each gets $800,000 when they reach age 18.

The money has opened some family rifts. While never close to her father, who left Kathy’s mother when she was 6, their relationship worsened. She believes he overcharged her for doing some brickwork and installing sprinklers in her yard after she lent him $100,000 to buy a house in the Hamptons.

Also, Kathy lavishes possessions on her sons, Daniel, 16, and Alex, 14, and hosts parties for their friends, trying to compensate for the fact that they’ve lost their father.

But the money seems to have the same effect on them. Her daughter Jessica was 19 when Dan died and immediately got her $800,000 share. She’s already spent most of it on clothes, vacations and friends, she said.

Spending problems are “not uncommon” among 9/11 families who received big cash payments, said psychologist Paula Madrid, director of Columbia University’s disaster-related Resiliency Program, which serves many 9/11 families and victims.

“I’ve seen it very often,” Madrid said. “Some spend the money right away on luxuries like cars and furs. They also give it away, out of survivor’s guilt and a desire to help others in need.”

The compulsion to shop, she believes, stems from anxiety. Spending is a pleasurable “distraction” from unresolved grief, she said.

“People are trying to fill a void which will never be filled by money,” Madrid said.

A stay-at-home mom for the past 20 years, Trant is down to her last $500,000 and worried about her future. She has partnered with her best friend, a laser technician, to open a hair-removal and cosmetic tattoo shop in East Norwich, The Dutchess of Dermis.

She agrees she needs counseling.

“I really don’t have the will to live,” she said.

Kathy Trant has spent family 9/11 money on items such as:2,700-square-foot home expansion/renovation: $1.5 million

Designer shoes: $500,000

Backyard basketball court/ pool/hot tub/patio: $350,000

Trip for six to Super Bowl: $70,000

Tahoe SUV: $60,000

Jewelry: $50,000

Four Caribbean cruises: $50,000

Trip to Bahamas for 20 friends and relatives: $30,000

Three breast jobs for friend/relative/stranger: $23,000

Pool table: $20,000

Four Peter Max paintings: $15,000

Trip to Las Vegas with 10 friends; $15,000

Fendi, Judith Leiber handbags: $5,000 each

Versace, Capelli gowns: $5,000 each

Yorkie dog: $3,500

Botox injections for friends: $2,000

Tattoo of American flag and “9/11” on her back: $500

* COMING TOMORROW – 9/11 KIDS WITH CASH