McCready filed a civil suit last month in the Davidson County Circuit Court based on a criminal case against William McKnight, the Nashville Tennessean reported Thursday.
McKnight is accused of breaking into McCready's home and beating her.
The lawsuit claims McCready was left with a "blanket mistrust" that harmed her business relationships and as a result, she said, her earning capacity has greatly diminished.
"One of the problems is that, literally, venues worried about whether Michael McKnight would show up and someone would get hurt," said Paul Berg of Media Plus, representing McCready. "It's been very interesting to see how difficult it's been to even put her someplace to do a free show to raise money."
McCready pleaded guilty in 2004 to fraudulently obtaining the drug OxyContin, was arrested in 2005 for drunken-driving and has twice attempted suicide, the newspaper noted.
Her son with McKnight is 2-months-old.
NBC reportedly holds celebs hostage to Jimmy Fallon's show
Aaron Carter is still in love with Hilary Duff