Dame Joan Collins says she has felt unsupported during her career.
The actress, 87, told ITV’s The Jonathan Ross Show she “went through the jungle alone”.
Next month marks 70 years since she started acting, Dame Joan told the programme.
She described reaching the milestone as “unbelievable”, adding: “I was 17 and I did this dreadful movie, Lady Godiva Rides Again.
“By 20 I was put under contract at 20th Century Fox.
“I got on a great big jet to go to America all by myself at 20.”
Dame Joan, who recently starred in Christmas film The Loss Adjuster, also discussed the challenges she had faced during her career.
She said: “I never had anybody, I never had the great agent, or great husband – before Percy [Gibson] that is – I never had anyone who was really supportive of me.
“I had a very tough time all my life. As an actress, when you’re very young and pretty, you’re not taken seriously as an actress.
“Vivien Leigh told me this. She said, ‘People only started to think I could act when I started to lose my looks.”
She added that her father, who was an agent, told her not to be an actress because she would be “finished” by her mid 20s.
“Well daddy, I proved you wrong,” Dame Joan said.
She also paid tribute to the late actress Dame Barbara Windsor, who died last week aged 83.
Dame Joan said she met the EastEnders star “many, many times”.
She added: “She was always great fun, with the cackle laugh.
“We did something for the Queen. We did a lot of things together.”
The Jonathan Ross Show airs on Saturday at 9.25pm on ITV.