Asked by Lindemulder's lawyer if he recently hit rock bottom – James's stint in rehab earlier this year followed his splitting with wife Sandra Bullock – James replied, "Yes. To some degree."
But, "I am continuing treatment," James, 41, said in regard to seeking professional help for his problems.
James also said he "was a victim of childhood abuse and trauma" and that he "pretty much raised myself."
He previously revealed he was abused by his father and said that the shame of it drove him to cheat on Bullock.
Choking up and his voice breaking, James said he has "been living in the shadow of that my whole life." He added, "I've always hated my sister, but as bad as I got beat, she got it even worse." James also testified he became an alcoholic at the age of 14 or 15.
"That was a big Band-Aid for the pain I was in," he said in court. "I drank until I was 30."
The motorcycle mogul also said that during his month-long stay in rehab, Sunny, his 6-year-old daughter with Lindemulder, stayed with Bullock in Austin.
The judge in the case is to decide whether allowing Sunny to move to Texas with James is in the child's best interest.
Reporting by KEN LEE