The fragile star -- who has been reportedly treated in the past for eating disorders and drug and alcohol dependency -- is said to be haunted by memories of her former flame as Ledger's image is plastered across billboards, newspapers, TV screens and magazines in the US, with his film The Dark Knight breaking box office records.
In Grazia magazine, which goes on sale tomorrow, the 22-year-old actor reportedly confided to sources that she and Ledger, 28 , were secret lovers when he died of an accidental prescription drug overdose in his New York apartment on January 22.
It is apparently the first time she has confirmed their relationship, despite Ledger being romantically linked to supermodels Gemma Ward and Helena Christensen at the time of his death.
``I'm just completely shattered about Heath,'' Olsen is quoted as saying in Grazia.
``I loved him so much. We had this amazing connection and now he's gone. I just can't get over him.''
Friends also told the magazine Olsen felt she had been made the villain and was convinced she is hated by Ledger's family, friends and fans, particularly in Australia.
The actor faced intense media scrutiny and public outcry after New York police confirmed Ledger's masseuse, Diana Wolozin, speed-dialled Olsen four times after finding the actor unconscious, but she did not call for an ambulance until nine minutes after her first call to Olsen.
Olsen, who has an apartment around the corner from Ledger's in the trendy New York district of Soho, was in Utah for the Sundance Film Festival at the time, but sent her security team to his apartment.