The eight-part Lindsay comes to a close on Sunday – and promises a shocking revelation

The two-hour finale of Lindsay seems primed to keep people talking about Lindsay Lohan‘s struggle to revive her career and stay sober.

“It’s a really f–––––-up disease and it’s really scary,” she says through tears as she talks about alcoholism in this sneak peek from the finale.

The episode hints at Lohan’s bout with temptation as she sits at a party while champagne flows around her, and tackles the fallout from a leak of her supposed list of former lovers. It also promises to answer why Lohan briefly went M.I.A. during production on the series.

“For those two weeks that I took off, no one knows this ” Lohan says, as the spot teases its dramatic reveal.

Earlier in the series, Lohan, 27, admitted that she fell off the wagon and drank a glass of wine.

In an interview with Ellen DeGeneres in March, the Lohan revealed that doing the documentary series “was really scary at first and I didn’t expect it to be what it became.”

Ultimately, however, Lohan said she was thankful she signed on for the show.

“It got really overwhelming, but it’s probably one of the best things that I’ve allowed myself to do,” she said.

The Lindsay series finale airs Sunday (9 p.m. ET) on OWN.