Selma Blair: Outburst on Flight ... Removed by Stretcher

Selma Blair was taken off a Delta flight Monday on a stretcher after losing control ... TMZ has learned.

Witnesses on a flight from Cancun, Mexico to LAX tell us, Blair was in first class and drinking wine. The witnesses say it appeared she combined something -- perhaps medication -- with her glass of wine.

We're told she suddenly started crying, "He burns my private parts. He won't let me eat or drink."

The witnesses say she continued, "He beats me. He's going to kill me."

We're told 2 nurses on board came over to help and checked her bags for pills.

Our sources say the pilot radioed ahead and told the tower there was a passenger on board who had been mixing alcohol and meds.