"I am. I am an alcoholic," Vargas told Good Morning America's George Stephanopoulos. "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. The amount of energy I expended keeping that secret and keeping this problem hidden from view was exhausting."
But the "staggering burden" eventually took its toll on the 51-year-old news anchor.
"You become so isolated with the secret and so lonely, because you can't tell anyone what's happening," she said, adding that she she knew she needed help when she showed up for a 20/20 shoot and realized she was "in no shape" to do the interview.
"I dealt with [my] anxiety, and with the stress that the anxiety brought by starting to drink. And it slowly escalated and got worse and worse," she said about her progressive addiction. "I felt like I had to be, you know, perfect, which is ridiculous. Nobody's perfect."
Though after going to a rehab center that specializes in treating trauma, staying for 28 days, then leaving against doctors' advice and then coming back five days later to finish, Vargas said she now feels she has a strong support system in place.
"I'm part of AA (Alcoholics Anonymous). I have a sponsor. I have great, great friends who I love and who love me," she said. " ... Alcohol for me is no longer an option. ... There's been a real spiritual component for me in all of this. Reach out to somebody who can talk you through that rotten day."