From PEOPLE Magazine Click to enlarge
When Carrie Fisher was cast as Star Wars' intergalactic hottie Princess Leia in the early '80s, the 19-year-old actress was promptly ordered to whittle 10 lbs. from her already petite 105-lb. frame. "I went to a fat farm," says the 5'1½" Fisher, who stayed two weeks and lost 5 lbs. "It was miserable."

Now 54, Fisher is faced with a wardrobe problem that's far, far away from squeezing into a two-piece. "I have to wear fat clothes," says the actress, who-after years of poking fun at everything from her past drug and alcohol addictions to those iconic cinnamon-roll-shaped side buns-is finally opening up about one of her toughest personal struggles yet: her weight. "I'm embarrassed," admits Fisher, who hit 180 lbs.-her heaviest ever-last year. "You can see it in my face. I constantly wear leggings. I've got cellulite on my arms!" Now the new face of Jenny Craig, Fisher vows to get her body-and her self-esteem-back. "Being fat," she says, "is humiliating."

Sitting cross-legged on her bed in her cozy L.A. home, Fisher-the daughter of movie star Debbie Reynolds and the late crooner Eddie Fisher-says her transformation was gradual. She trimmed down for her 2006 one-woman show Wishful Drinking, which inspired her bestselling 2008 memoir. But once she started touring, "I went for three years without exercise," says the comedian, whose daily diet might include seven regular sodas, multiple peanut butter protein bars and ice cream or other sweet treats. And Fisher claims that prescription mood stabilizers-which she continues to take-have made staying trim "60,000 times more difficult, since every med I take has weight gain as a side effect."

Soon the gregarious star was too ashamed to leave the home she shares with daughter Billie, 18 (Dad is Fisher's ex, talent agent Bryan Lourd). "I won't go out, especially if there are photographers," says Fisher, who refuses to watch her own HBO comedy special. "I can't look at myself. I have to listen to it from the next room."

But she couldn't hide from her problem for long: One day last year, "I got up and my leg was numb. I thought, 'There's something wrong,'" says Fisher, whose doctor warned that with her high cholesterol and her family's history of heart trouble, she needed to change. Shaken by the death of her dad in September, she decided, "I can't be like this anymore."

Fisher looked into lap-band surgery, but after learning she didn't meet the weight requirements, she signed up for Jenny Craig because "I'm not good at saying, 'I can have 8 oz. of protein.' This plan does it for you." Already 12 lbs. lighter since starting in late November, Fisher hopes to shed 30 lbs. or more. But she won't be back in that bronze swimsuit. "You're not supposed to be in a bikini at my age!" she says. "A little black dress would be fine." Ultimately, she says, "I just want to be able to look at myself in the mirror again."