Exclusive Book Excerpt Prairie Princess

updated 06/15/2009 AT 01:00 AM EDT

originally published 06/15/2009 AT 01:00 AM EDT

I spent a lot of time trying to distance myself from Little House on the Prairie," says Melissa Gilbert, who played Laura (a.k.a. "Half Pint") on the hit series from 1974 to 1983. But now the 45-year-old mom of two boys and two stepsons feels just fine about looking back. In the fall, she will return to play Ma in a musical stage version of Little House, touring through 2010. And she has a new memoir, Prairie Tale, that encompasses both her pigtailed TV years and what came after: high-profile romances, a marriage that fizzled, a series of plastic surgeries, a drinking problem. Why tell all now? "I'm comfortable in my own skin," she says. Married for 14 years to actor Bruce Boxleitner, she lives in L.A. and serves on the board of the Children's Hospice and Palliative Care Coalition, a charity that promotes better care for terminally ill kids. "Bruce said we count my life experience in dog years," says Gilbert, who talked with PEOPLE's Moira Bailey. "He said, 'Basically, Melissa, you're 148.'"

I was 6 when my curly red pigtails and slightly buck teeth began to charm one director after another. Dozens of girls would come in for each audition and the group would be cut down to the same handful: Jodie Foster, Kristy McNichol, [My Three Sons'] Dawn Lyn and me. I was 9 when I went on a cattle call for a series based on the Little House on the Prairie books by Laura Ingalls Wilder. I read for Michael Landon. I remember thinking, "Oh gosh, he's really handsome."

Gilbert won the lead role of Laura, and shooting began in 1974.

Once I slipped on the dress I felt transformed. But not all the acting was pretend. The on-screen rivalry between [sisters] Mary and Laura played off of the competitiveness that existed off-camera between Melissa Sue Anderson and me. The lines also blurred between Mike and me. There was nothing I feared more than disappointing him.

In the ensuing years, I've realized his influence on me extended beyond the set. As a kid, I didn't know he sipped vodka from his coffee mug almost as frequently as he pulled me into his sweat-soaked torso for a bear hug, but I'm sure he's one reason why, as a young adult, I almost always picked men who smelled like alcohol.

She first met a "cute" 14-year-old Rob Lowe in a TV studio hallway, but they didn't connect romantically until 1981, when she was 17.

I fell instantly, hopelessly and stupidly in love. We went from first date to instant couple. I felt like I was starving for Rob. I wanted to bite him. He felt the same way about me. He wrote me poetry. He cooed the sweetest messages into my answering machine.

We devised a system where Rob would come for dinner pretty much every night. Then he would say good night and park down the street, where he would sit in his car for 30 or 40 minutes. I would excuse myself to go to my room and watch TV in bed. In the meantime I would be listening for a rustling outside my window. It would be Rob climbing up the ivy-covered wall outside the house. He spent the night without anyone ever knowing he was in my bed.

After a split, Lowe dated Monaco's Princess Stephanie but returned to Gilbert in 1986 with a marriage proposal. Before the wedding, Gilbert discovered that she was pregnant.

A baby. My baby. Mine. And Rob's. Oh God, the wedding! No way was I walking down the aisle with a bulging stomach and a train of whispers. What was Rob going to say? I tried to imagine his reaction. Surely he would be happy. Right? I was beyond happy. With my cheek pressed against his face, I whispered, "I'm pregnant."

Silence. I pulled back from him just enough to see his face.

"Rob?"

Finally, with his voice trembling and tears in his eyes he said very softly, "I can't be a father." Before I could respond, he said, "I can't be a husband. I'm so sorry."

I put my arms around him and we cried together. Both of us knew this time it really was over.

What the hell was I going to do? [An adoptee myself], I wasn't going to repeat my birth mother's decision. I would never give up my own child. Rob assured me that he would honor whatever decision I made. I would love to say that I finally did reach a conclusion, but I didn't need to. I woke up one morning and began spotting—I was having a miscarriage. I let nature take its course.

I had lost my baby and my relationship with Rob. Now I was completely, totally alone, and it hurt like hell.

Gilbert says she chose to share this episode because "it was one of the more painful experiences in my life, which created one of the biggest growing periods of my life." She says she alerted Lowe before publication, in part to avoid "any discomfort" to his family.

Following the end of a five-year marriage to actor Bo Brinkman (with whom she has a son, Dakota, now 20), Melissa was set up with Scarecrow and Mrs. King star Bruce Boxleitner.

Now I was with a guy who was absolutely my equal. Bruce was a grown-up, but he still had that bad boy glimmer in his eyes. I had finally met my match.

In 1995 their son Michael was born 12 weeks premature. He was soon thriving, but Gilbert was dealing with cumulative stresses—including continuing tensions with Brinkman—by turning to alcohol.

Drinking was the calm from the daily storm inside my head. By the end of a typical night, I would have gone through two bottles of wine myself. Bruce had no idea how much I consumed. At home, I had my system down to a science. I would pour a glass of wine, take a few sips and sneak back into the kitchen and fill it to the same level. One night a friend was over for dinner. I passed out face-down in the dog bed. I woke up in the guest room. Bruce was sitting on the bed, staring at me. I broke into tears.

"I have a drinking problem," I said.

A therapist and, later, AA meetings helped her get sober.

By summer 2008 my mind and heart were in the best place of my life. I had over three years of good, solid sobriety. And I began an exciting new chapter doing something that had terrified me all my life: singing. I signed on to do a musical version of Little House on the Prairie in Minneapolis. The strangest part was grappling with playing Ma instead of Laura. Talk about an identity crisis. [On opening night] I walked into a crowd of autograph seekers who shouted, "Laura! Laura! We love you, Laura!" Ultimately, it didn't matter what people called me. Instead of worrying about who I was, the key was to focus on who I could become.

From Our Partners