The 73-year-old actress - who has been married three times - explained after battling eating disorder bulimia throughout her teen years, losing her mother to suicide at the age of 12 and having a distant relationship with her father, actor Henry Fonda, she was "so unhappy".
She said: "If people can learn anything from me it's that I've not always been happy and I've not always been strong.
"When I was 20, I thought I was going to die of loneliness, I was so unhappy. But as I've got older, I've found myself growing happier."
However, Jane admits she blames her '12 Angry Men' star father - who was married five times - for her bulimia after "objectifying" her from a young age and bringing her up to "feel fat".
She added to You magazine: "I was brought up to feel fat, though my father wouldn't tell me directly - he'd get one of his wives to tell me that I shouldn't wear a bikini.
"I was a product of objectifying parents and also a product of the 50s, when the way a woman looked was so important. It's why I pay attention to my appearance now. I believed that to be loved you had to be perfect, and even though I've got over that now, it took a long time."
Labels: Hollywood, Jane Fonda