Looking back at the time when she suffered a devastating eating disorder, Jamie-Lynn Sigler says it's like she was a different person.

"It's hard for me to even recognize who I was," the former Sopranos actress, 26, tells PEOPLE. "My reality was so warped. ... I knew I had a problem and wanted to get better, but I was not able to let go of my habit."

She recalls one moment in particular – a meal with her family, when her father begged her to have some cake. "I remember rationalizing that if I had that one piece of dessert, the next morning I would wake up and weigh 400 pounds," she says. "It sounds so wild, but for me it was true."


That 'Deepest, Darkest Place'
Sigler was honored last Thursday in New York by the National Eating Disorder Association (NEDA) for her work as an ambassador for the group. In her speech, she recounted her struggle to escape that "deepest, darkest place" – and her efforts to have eating disorders seen as more than a "superficial disease."

These days, Sigler remains in recovery, and works to keep the bad habits at bay.

At one time, "I knew every calorie that entered my body, and I tried to measure every calorie that I could burn," she says. "So for me, any sort of regimen, any sort of ritual or rule when it comes to dieting or exercising, is bad for me."

She also used to over-exercise, but has worked out a healthy balance in that area, too.

"I have a wonderful friend who does yoga with me," she says. "When I go home to Long Island, my mom and I take the dog and go hiking. It's nice to be outdoors."