AceShowbiz - Sarah Ferguson, the Duchess of York insists the royal family was quite right not to invite her to Prince William's wedding last month - because she has ostracized herself from The Queen and company.

The former wife of Prince Andrew and mother of princesses Beatrice and Eugenie spent the royal wedding day in a remote Thai jungle trying to come to terms with the royal snub, and she admits she wasn't really expecting an invite - because of all the mistakes she has made.

No longer an official member of the royal family, Fergie has battled longtime legal woes and was famously exposed for attempting to arrange a business meeting with Andrew - for a fee. She accepts she has been a thorn in the royal family's side for some time.

Speaking on a taped episode of "The Oprah Winfrey Show, Ferguson says, "I went through the phase of feeling so totally worthless and it was quite right that they didn't invite me... I felt that I ostracized myself by my behavior."

And she didn't want to be in London for the wedding, which her ex and daughters were invited to. She adds, "I chose to go and be in Thailand in a place called Camelia and... the jungle embraced me... I beat myself up most of the day thinking and regretting, 'Why did I make such a mistake.. Why have I made so many mistakes?' I did spend a good three hours on that."

The 51-year-old's "Oprah" appearance will air on Wednesday, May 11 in America - and she admits it was difficult to be excluded from the royal wedding: "I wanted to be there with my girls and... to be getting them dressed and to go as a family. Also, it was so hard because the last bride up that aisle was me."

She admits her ex-husband had some comforting words for her, adding, "We were talking all morning and he was saying, 'It's OK. Just remember we had such a good day. Our wedding was so perfect'... He made me feel very part of the day on April the 29th."

However, Ferguson did catch the ceremony - and thought royal bride Catherine, Duchess of Cambridge looked "utterly beautiful".