The Mercury News reported that Lockyer admits to writing an email to a reporter last week accusing her husband, state Treasurer Bill Lockyer, with buying and supplying her with drugs years ago.
His office has denied the allegation.
Lockyer said her husband became so upset with her obsession with an ex-boyfriend that he told her to "go ahead and commit suicide."
A spokesman for the state treasurer says the couple had a heated argument and both said hurtful things they regret.
Lockyer admitted that she was planning to attempt suicide after entering a Marin rehab center in February but that she was interrupted by a clinic worker.
Lockyer resigned on Friday to focus on her family.