That's the picture the singer paints in a legal document made public Monday by the Hollywood Reporter. In a transcript of an April deposition, Thicke, 37, reveals he "didn't do a sober interview" while promoting his single with Pharrell Williams last year.
"Every day I woke up, I would take a Vicodin to start the day and then I would fill up a water bottle with vodka and drink it before and during my interviews," he said in the file, also obtained by PEOPLE.
The R&B crooner also touches on his very public split from Patton, 38.
The actress left Thicke in February following rumors of his infidelity (he was photographed grabbing another woman's behind at a nightclub) and his racy "Blurred Lines" performance with Miley Cyrus at the MTV Video Music Awards.
"Do you consider yourself an honest person?" a prosecutor asked him during the deposition.
"No. That's why I'm separated," Thicke responded, later adding, "I told my wife the truth. That's why she left me."
The legal battle stems from allegations that Thicke and Williams, 41, ripped off Marvin Gaye's "Got to Give It Up." The stars are being sued by Gaye's family for royalties, and they counter-sued.
Thicke testifies that he had nothing to do with writing "Blurred Lines," claiming that he lied in multiple interviews in which he took credit for the song's success (and named Gaye as an influence) out of career jealousy.
"I was high and drunk every time I did an interview last year," he said. "So there are some quotes I don't remember saying, but I do generally remember trying to sell the public on the fact that 'Blurred Lines' was my idea in some way."
Thicke has been sober from Vicodin for two months but still drinks, he said.