A badly shaken WHITNEY HOUSTON is fighting for her life against deadly emphy­sema – and her daughter is waging a desperate battle to save her.

Doctors have told the 47-year-old singer she’s suffering from the early stages of the frightening lung disease – and informed her in no uncertain terms she must immedi­ately quit smoking or she will die, The ENQUIRER has learned exclusively.

Tragically, it’s fallen to her 18-year-old daughter Bobbi Kristina – who just recently got out of rehab – to stop her beloved mom from digging her own grave.

 During Whitney’s world tour last year, critics and fans were shocked and mystified when she became breathless on stage and had to halt performances while she recovered.

 “She’s developed em­physema – and her doctors are warning her she’ll die a horrible death,” a friend told The ENQUIRER exclusively.

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