From PEOPLE Magazine Click to enlarge
No one is more embarrassed by the stories of Shannen Doherty's rebellious antics than the actress herself. "There are moments when I'll drop my head in my hands and go, 'What was I thinking?' " says Doherty, who became a '90s tabloid fixture due to her raucous late-night partying, two marriages (that each fell apart in less than a year), allegations from an ex-fiance that she tried to run him down with her car, a lawsuit over writing bad checks and getting fired from her hit show Beverly Hills, 90210. "I was an absolute moron," the actress freely admits. "But if it weren't for the mistakes I made, I wouldn't be where I am today."

Sitting in the backyard of the sprawling Spanish-style Malibu mansion she shares with her husband of six months, photographer Kurt Iswarienko, Doherty is now clearly-and finally-in a happy place. "It's time people get to know the real me," says the actress, who hopes to do just that with her new WEtv reality series, Shannen Says. The kinder, gentler Doherty, 41, now even laughs off a recent Internet report that called her "fat"-in fact, she's put on a few pounds in an effort to get pregnant. "Go ahead!" she says. "If I'm able to have a child because I'm a little fatter, then great."

It took her decades to develop this laid-back attitude. In the early '90s, Doherty became a star as good-girl-turned-brat, 90210's Brenda Walsh. After being fired from that hit, she got a second chance in 1998 on the WB drama Charmed-where she feuded with costar Alyssa Milano and quit after three years. Says Doherty: "I burned a lot of bridges and hurt people."

But her wild public behavior was masking a private pain. Doherty's father, John Thomas, was severely ill, and the actress, who began working at age 10 on shows such as Little House on the Prairie, was supporting her family. "I wanted him to have the best medical care possible," she explains. "I had to be so responsible in that area of my life that I was acting out in other areas." When her dad, who had suffered multiple strokes, died in 2010 at 66, "it completely changed me," she says, tearing up. "The walls I'd put up to protect myself came down." She's since reconnected with several costars, including 90210's Jennie Garth, whose own rough patch weathering a divorce elicits Doherty's empathy. "I feel for her," Doherty says. "And more importantly, I feel for her kids."

Since marrying Iswarienko, 37, last October after meeting him at a photo shoot in 2009 (their wedding is the subject of Shannon Says), the couple has settled into married life and are building a house, with a nursery. Doherty isn't pregnant yet, but says she can't wait to be a mom. "I feel a peace I've never felt before," she says. "Now I'm ready for the next chapter in my life."