ABC News anchor Elizabeth Vargas opened up about her alcoholism and recent treatment in rehab to George Stephanopoulos on “Good Morning America” Friday, saying that keeping the secret from co-workers and friends was “exhausting.”

“I am an alcoholic. It took me a long time to admit that to myself. It took me a long time to admit it to my family, but I am,” she said. “The amount of energy I expended keeping that secret and keeping this problem hidden from view was exhausting.”

Vargas, 51, said she started suffering from daily panic attacks as a child, which continued into adulthood.

“I dealt with that anxiety, and with the stress that the anxiety brought by starting to drink. And it slowly escalated and got worse and worse,” she said.

She previously went to a rehab center and stayed for 28 days then left against doctors’ advice. She went back last fall and stayed until the doctors said she was ready to go home.

“This isn’t what I want to be known for, but I’m really proud of what I did,” Vargas said.

More of her story will air Friday at 10 p.m. on “20/20.”