The two new songs on Sarah McLachlan's upcoming greatest hits album -- "U Want Me 2" and "Don't Give Up on Us" -- come from an extremely personal place.

"I'm separating from my husband, so these are the songs about that," McLachlan told Billboard.com. She's been married to Ashwin Sood, who plays drums in her band, for 11 years. The couple, who reside in Vancouver, has two daughters, six-year-old India and Taja Summer, 14 months.

"I wasn't planning on saying anything," McLachlan added, "but it's gonna come out at some point. I haven't said anything about it because I've been terrified to, but I figure ... there's no good time to say it, so I just said it."

McLachlan called the situation "pretty gross" but did not elaborate on reasons for the separation or the couple's future plans.

The two songs appear on "Closer: The Best of Sarah McLachlan," which comes out Oct. 7 in both a single-disc version and a two-CD deluxe package. The video for "U Want Me 2" premiered Wednesday on Amazon.com.

McLachlan wrote both songs with her longtime producer Pierre Marchand. She described "U Want Me 2" as "about that really uncertain, confusing place at the end of a relationship when there's no communication or closure, everything's still up in the air and there's a lot of anger and sadness. It's sort of that working through 'How do we move forward ... with some dignity and grace."

"Don't Give Up," she said, is "pretty self-explanatory, basically just a plea to give it another chance and keep trying."

McLachlan is planning a series of TV appearances to promote "Closer." She said she's also working on more new material and hopes to have a new album out within the next two years.