Bobbi Kristina -- My Dad is LOSING His Battle with Alcohol

Bobby Brown is NOT conquering his demons ... the demons are conquering him ... this according to his daughter Bobbi Kristina.

Whitney Houston's daughter was leaving LAX with her "brother" Nick Gordon when we asked if her father is "rising above" his alcohol issues now that he's checked himself into rehab.

"'Rise above' is not the word you should use" ... Bobbi told us ... "Not at all."

TMZ previously reported, Brown checked himself into a treatment center earlier this week ... after struggling with booze for years and getting a DUI back in March.