"I was bold enough to say, 'Yeah, I like a girl. And?' That put her in a situation where she was being attacked every day. That's not fair. And what am I left with? Heartbreak," explained Lohan, who previously dated actor Wilmer Valderrama, singer Aaron Carter and restaurateur Harry Morton. "That was three years ago. It was my last serious relationship."
Lohan, 26, and Ronson, 35, have kept in contact since their March 2009 breakup. "I needed to love myself first before I could be with anyone. And I was going through a lot. Two toxic people cannot be together. End of story," the Liz & Dick star tells Us. "We're friends now. That's how it started, so I think that's what's meant to be."
Currently single, Lohan says she's determined to get her career back on track. "I'm happy. I just did three movies in a row and I'm not even tired," boasts the actress, who next appears in Scary Movie 5 (alongside Charlie Sheen) and The Canyons (alongside porn star James Deen). "I want to do the next one. It took a while to get back to that."
For more from the actress' exclusive interview -- including what she learned from playing the late Elizabeth Taylor, her much talked-about family squabbles, her plans for adoption, and much more! -- pick up the new issue of Us Weekly, on stands now.