Mariah Carey Reportedly 'Thrilled' With 'Fresh Start' and Weight Loss

Mariah Carey is preparing for her new Las Vegas show and has never been happier about a chance for [...]

Mariah Carey is preparing for her new Las Vegas show and has never been happier about a chance for a "fresh start," a source close to the pop star said Friday.

A source told Entertainment Tonight that Carey is "thrilled" by her recent weight loss.

"She seems to be exuding happiness and she is," the source said. "She has had big changes in her life for the better. Both dropping her manager, Stella [Bulochnikov], and coming clean about her struggles with bipolar disorder have been a huge relief and it shows."

Carey still has not publicly discussed her weight loss, but it was discovered she had gastric sleeve surgery in Beverly Hills, California in November. She also dropped her former manager, Stella Bulochnikov that month.

In April, the 48-year-old told PEOPLE she was diagnosed with bipolar disorder in 2001.

The source told ET Carey is getting the "fresh start" she needed ahead of her new Las Vegas show, The Butterfly Returns. She told Jimmy Kimmel last week that the show will focus on rarely performed deep cuts from her career. She even toyed with the idea of taking requests from the audience.

"She has always struggled with her weight. In the last five years it has become more and more difficult for Mariah to shed the pounds," the source told ET. "She has a huge career, children, and she has been through big changes with her team. It's truly been an emotional roller coaster and that always affects her weight, both gain and loss."

Carey has gone on and off diets in the past, but the source said Carey is focused on keeping healthy and getting off her "dieting roller coaster."

"She is focusing on new music and she is thrilled about her Vegas residency," the source continued. "She often tells friends she wants to be the queen of Vegas and she seems to be on her way."

Carey also has a new man in her life. She is dating Brian Tanaka, who celebrated his 35th birthday in April. She is raising twins Morrocan and Monroe with ex-husband Nick Cannon.

While the "All I Want For Christmas Is You" singer has much to be happy for, she is facing a lawsuit from Bulochnikov. In April, her lawyer, Pierce O'Connell, said she was preparing to sue Carey for violating the U.S. Civil Rights and and the Fair Employment and Housing Act.

O'Donnell told The Blast the lawsuit could be a "blockbuster expose" if it goes to trial. He said Carey's bipolar disorder reveal was a "big lie" and accused the singer of being "addicted to alcohol, prescription pills and marijuana."

Carey's representative called the claims "frivolous and baseless," and vowed to fight them.

Photo credit: Instagram/Mariah Carey