Tara Reid -- How Drunk? SOOOOO DRUNK

Tara Reid is most definitely nursing a Wednesday morning hangover right now ... 'cause she hit the clubs so hard last night, she could BARELY STAND on her way out.

It's your classic ... "girl walks into a bar, girl chugs a bunch of liquor inside of the bar, girl gets so plowed she needs help leaving the bar" story.

The good news -- Tara didn't get behind the wheel ... she had a driver take her home.