"I felt loved and supported and it made the time go by," Urban said Monday in a video message on his Web site. "I never felt alone."
His wife, actress Nicole Kidman, was "extraordinary" while he was undergoing treatment, as were his family and friends.
What started out as a 30-day program in October grew into 90 days at a Betty Ford clinic, he said, because he had a lot to learn about himself and "how I got to be in the position I was in."
Why he landed in rehab wasn't Earth-shaking. "It was a lot of small moments that started to accumulate," he said. "I was making my life unmanageable."
Urban said he was looking forward to playing music and touring again so he could thank his fans for their support.