The intimate story of how a struggling waitress named Michelle Phan nabbed 4.5 million YouTube followers and a major makeup deal. As told to Geraldine Campbell.

Phan, 26, with her new makeup line, Em. Sweater, Sandro; skirt, Rachel Zoe.

Seven years ago, in my first semester at college, the professors handed out MacBook Pros. With mine I filmed a seven-minute tutorial on "natural makeup"—just me, my laptop, and a cup of coffee. When, a week later, it clocked 40,000 Web views, I knew people were connecting with it, so I kept going. That moment changed my life.

At the time, I was keeping a personal blog in which I depicted myself as the girl I wanted to be, with money and a great family. But it was all a veneer. In reality my life was hard, and I was struggling with insecurities I'd had for years.

You wouldn't exactly call my childhood stable. When I was growing up, my father constantly gambled away our rent money. Every few months we'd get evicted and move. My brother and I never had the same beds for long, or even the same tree outside to swing on. Then one night after a big loss, my father just disappeared. It was more than 10 years before I saw him again.

My dad and I had been close—he called me Tuyet Bang, Vietnamese for avalanche, because of my nonstop energy. I took a lot from him, like being a risk taker, and I know how much he loved my mother. Their families were like the Montagues and the Capulets—he was from northern Vietnam, she was from the central countryside, yet they ran off together.

After he left, my mother was heartbroken. But she remarried, and our relationship with my stepdad was good... at first. They had a daughter, my little half-sister, Christine. But bit by bit he became very controlling of my mother. Eventually, the four of us moved out, and at age 17, I started working as a hostess to supplement my mom's income as a nail technician in a salon. We could barely pay rent, and we had no furniture; I slept on the floor, my clothes in a basket beside me. We couldn't afford dressers.