Selma Blair reportedly LOST IT mid-flight on her way back to LA from Mexico on Monday -- screaming strange things as she was restrained and held for emergency medical staff to remove her from the plane when they landed at LAX.

Blair allegedly drank lots of wine during the flight and was seen mixing some sort of medication with her alcohol before becoming belligerent. She reportedly screamed "He burns my private parts. He won't let me eat or drink. He beats me. He's going to kill me." TMZ reports. A pilot reportedly radioed ahead to ground crew to have EMTs on hand and as soon as they landed, medical personnel boarded the plane and cared Blair off on a stretcher.

Blair was vacationing with her baby daddy Jason Bleick at the Hard Rock Hotel in Cancun. They even posed for a photo at the resort, looking quite lovey-dovey ...

Hard Rock Hotel Rivera Maya

WTF??!!