Onpaper, she’s worth some $350 million, but Mariah Carey isn’t above mortgaging her apartment to get some cash. A recent report revealed that the 55-year-old is $18.6 million in debt because of taking loans out against her $30 million pad in New York City’s posh Tribeca neighborhood. Now sources tell Life & Style that the “All I Want for Christmas Is You” singer is having to cut back on her outrageous spending — and the diva doesn’t like it. “Being able to spend money, and even waste money, gives her a lot of happiness,” says the insider. “She loves to throw her money around, if she’s feeling sad, she goes shopping. If she’s happy, she goes shopping.”

When her financial advisors try to put a stop to the spending, Mariah, known for her love of champagne and diamonds, can’t compute why. “She just rolls her eyes and accuses them of overreacting,” notes the insider. Perhaps she’s banking on her January residency in Las Vegas. After all, tickets are $2,700 a pop!