New York ( CNN ) -- South Carolina 's first lady , Jenny Sanford , said Monday that writing her much-anticipated memoir of her husband 's affair was a `` cathartic '' and `` cleansing '' experience . In an interview on CNN 's `` Larry King Live , '' Sanford called `` Staying True '' -- which hit bookstores Friday -- `` an honest account of the values I hold dear . '' It was her husband Gov . Mark Sanford 's loss of values that she blames on his much-publicized affair with an Argentine woman that was exposed by reporters after he disappeared for several days last summer . Staffers said he was hiking the Appalachian Trail , but he later admitted he was actually visiting his mistress in Argentina . `` It saddens me because I believed in him and a number of people believed in him , '' Jenny Sanford said Monday . `` I still believe he was a good person . ... Somewhere along the lines , he got off track , '' she said . `` He can get back on track , but it 's too late for the marriage . '' Jenny Sanford , who filed for divorce in December , said the divorce could be final as early as the end of this month . She said she found out about the affair in January 2009 when she discovered a letter her husband had written to his mistress . `` It was awful , '' she said . `` I literally was in shock . My stomach felt gut-punched . '' She said there had been warning signs , but she `` never expected anything like this . '' `` I felt in some respects that we had lost something that we would never get back , '' even as she initially considered staying with him , she said . `` Nobody takes a 20-year marriage and decides in [ a ] snap minute to throw it away , '' she said . `` I came to the decision very prayerfully and carefully over a number of months . '' Sanford , 47 , moved out of the governor 's mansion with their four boys in June . She has said through the entire ordeal that her priority is her children . `` The kids are resilient , and we 're back at home settling into a new , normal routine , '' she said of her sons , ages 11-17 . `` I feel like they 're going to do great . '' Asked whether she knows whether her husband is still seeing the Argentine woman , Jenny Sanford says she does n't know and does n't want to ask . `` I 'm just moving on , '' she said . `` I want to stay happy and positive and raise the kids to the best of my ability . ''
Argentina first lady Mark Sanford appears Monday on CNN 's `` Staying True '' . Sanford : `` He can get back on track , but it 's too late for the marriage '' Sanford admitted last year that he had an affair with an Argentine woman . On finding letter to his mistress : `` I literally was in shock . My stomach felt gut-punched ''