MELISSA GILBERT’s gold-digging French beau coldheartedly dumped her after realizing his famous girlfriend wasn’t as big a star – or as rich – as he thought she was!

The 48-year-old TV personality, who split from her husband, Bruce Box­leitner, last year, was swept away by playboy Thierry Gauchet after meeting him in Paris over New Year’s.

Thierry, 42, traveled to the U.S. in April to support Melissa when she competed on “Dancing with the Stars” with pro dancer Maksim Chmerkovskiy, and Melissa thought she’d finally found her soul mate.

BUT everything changed when Thierry returned to L.A. recently to help Melissa move into her new home – a much smaller place than she’d lived in when she was married.

“After he got a good look at the house, Melissa said he just stood there for a while,” revealed a source. “When he finally said something, it was, ‘Hmmm, awfully quaint’ – and then he left!

“And that was the last time she saw him!”

The sudden split has left the beloved actress shattered.

“Melissa has been crying and sleeping a lot and turning to family and friends for solace,” confided the source. “It dev­astated her because she thought they might get married one day.”

But Melissa can’t say she wasn’t warned.

As The ENQUIRER reported in our July 23 issue, pals of the former “Little House on the Prairie” star didn’t trust Thierry. They were suspicious that the vintage car dealer was using Melissa just to get a green card, which would allow him to live and work in the U.S.

“Thierry was a cad and a gold dig­ger,” blasted another insider. “He really thought Melissa was a big­ger star than she is, and that she was richer than she is.”

The source adds that although Melissa is currently wallowing in a poor-me pity-party, she’s better off without him in the long run.

“Thierry was mean and made fun of her, calling her ‘Grand­ma’ because she was a few years older than him,” noted the source. “He com­plained about her son and even her dog. She doesn’t know how lucky she is to have dodged that bullet.”