Lamar Odom hitting the bottle again is taking such a toll on Khloe Kardashian, she pulled the plug on taping "Kocktails with Khloe" this week ... TMZ has learned.

We're told Khloe told production she was too sick to shoot Thursday, but it's not because of the flu. Sources close to production tell us she's stressed out worrying about Lamar Odom's drinking. We're told she's been an emotional wreck.

TMZ broke the story ... LO is refusing to get treatment for addiction as Khloe insists he try something, even an outpatient program. We're told they've been fighting about it all week.

Our sources say enough was enough and Khloe just needed a break.