Part II: Armstrong said being forced to leave foundation "hurt like hell''

CHICAGO - Lance Armstrong says the most humbling moment in his doping scandal was being forced to step aside from the Livestrong charity he founded.

In part two of his televised interview with Oprah Winfrey on Friday night, he described the anguish of losing longtime sponsors like Nike and Trek, among others.

But he said Livestrong, a cancer-fighting foundation, was like "my sixth child."

"And to make that decision to step aside, it was big," he said. "It was the best thing for the organization, but it hurt like hell."

Armstrong admitted using performance-enhancing drugs to win the Tour de France seven times in part one, which aired Thursday night.

The interview was taped in Austin earlier this week.