After a recent report claimed she was battling a diet pill problem, Ramona Singer is having a "serious meltdown," Breaking Celebrity News can exclusively reveal.

According to a source close to Singer's Real Housewives of New York costar LuAnn de Lesseps, the single mom is indeed popping weight loss pills, but she thought nobody would spill the beans on her hush-hush habit.

"Ramona has lost her mind because her secret is out," the insider tells Radar. "She's been calling friends crying, and is irrational and erratic."