Julianne Moore had therapy after her "lonely" 30s.
The 'Still Alice' star admitted that she felt unhappy about her personal life when she was younger.
She said: "I was lonely. I don't think I felt happy. I didn't have the kind of personal life I wanted.
"I'd spent my 20s working hard and trying to get to wherever there was, which wasn't really anywhere. It was just a job, and I really wanted a family."
Through therapy, the award-winning actress realised she needed to focus more of her time and effort on her personal life and started working on balancing her career and relationships.
She added: "I discovered that was as important as my professional life. I didn't spend the time; I didn't invest.
"One thing I used to tell my women friends was, 'There's an expectation that your personal life is going to happen to you, but you're going to have to make your career happen. And that's not true: You have to make your personal life happen as much as your career.'"
The 54-year-old actress - who has Cal, 17 and Liv, 12 with her director husband Bart Freundlich - credits her success in both her career and her personal life to her own self, revealing that she "created her own life".
She added to The Hollywood Reporter magazine: "I totally believe it.
"I've been really lucky, but I feel I've completely created my own life."