Lindsay Lohan's Assistant -- I QUIT!!!

Lindsay Lohan needs all the assistance she can get ... no, really ... her assistant just quit.

Sources tell TMZ Lindsay's right-hand woman, Eleonore, quit Wednesday. Eleonore only lasted a few months and we're told she was "exhausted" and "had enough of Lindsay's demands."

We're also told Eleonore never had any time to herself and Lindsay would often force her to stay with her for days on end ... and then blame her when things went wrong.

Just one last warning for anyone interested in the gig -- we're told the job didn't pay much either. So here's how we're guessing the help wanted ad might look ...