AFTER ONE of the worst years of his life, piano man Billy Joel is happily in love and planning to propose marriage.

The entertainer has bounced back from rejection and loss in his love life and a desperate battle with booze to discover his dream woman Anne Maxwell, and find happiness again.

“Billy’s in love with Anne, a gorgeous blonde he met in Boston,” a pal told The ENQUIRER. “She really has mended Billy’s broken heart and he’s talking marriage.”

The ENQUIRER reported last summer that Billy was devastated when his former lover, TV news star Trish Bergin, spurned him to marry another man. Reeling from his loss, Billy began drinking heavily.

On the day pregnant Trish married, Billy checked himself into alcohol rehab at Silver Hills Hospital in New Canaan, Conn., and stayed 10 days. After he left rehab, Billy admitted he was lonely and told a reporter he wanted to move to Manhattan to meet women.

But he never made the move — because when he met Anne in Boston, he knew he’d found the woman he was searching for, friends say.

“Billy had to do a make-up concert in Boston in September, performing with Elton John at the Fleet Center,” said the pal. “Anne went to the show and a friend took her backstage and introduced her to Billy.

“It was love at first sight.”

Soon Billy, 53, was dating Anne, 28 — who works in sales for the posh Ritz-Carlton hotel — and bombarding her with flowers and love notes, the pal said. “He brought her a gorgeous pair of diamond earrings,” said the pal. “And when Anne flew back to New York for Thanksgiving with her parents, she invited Billy to meet them. Billy was nervous but they liked him and invited him back for a family Christmas.

“Now Billy says Anne has given him a reason to live again.”

Buoyed by love, Billy is rebuilding his life, those close to him say.

A friend of Billy told The ENQUIRER: “We’ve all been praying for Billy. And now he’s in love, and everyone is hoping for a formal engagement and then a spring wedding.

“Billy’s daughter Alexa knew her dad was lonely and when he suddenly fell for Anne, she saw his spirits change almost overnight. She loves him very much and wants to see him happy — and now her wish may finally have come true.”

Alexa, 17, is the product of Billy’s nine-year marriage to Christie Brinkley.