Princess Diana's former dance instructor, Anne Allan, has opened up about a tumultuous time in the royal's life in her new memoir, Dancing With Diana. Over a span of nine years, Anne became a trusted confidante and source of solace for the Princess of Wales as she attended regular dance classes.

Now 75, the dancer revealed that Diana once shared her marital woes with then-husband Prince Charles.

In an excerpt from the book published in People, Anne recalled: "Slowly, after a few more minutes of gentle sobbing, [Diana] said, 'I just can't seem to do anything right when it comes to my husband. I do love him so much and want him to be proud of me, but I don't think he feels the same way,'".

She added: "I just let her talk, not offering advice, but just listening. She continued, 'I don't understand why I am not enough for him; I think he prefers an older woman."

Allan noted that during their frequent interactions, she picked up on several "tongue-in-cheek" remarks from the Princess about her husband, leading her to suspect he was unfaithful. Anne tried to reassure Diana this wasn't the case, reports the Mirror.

However, as more truths emerged over the ensuing months, Diana felt increasingly inadequate, believing she wasn't "enough" for her husband who appeared to have rekindled his relationship with his old flame and current wife, now-Queen Camilla.

Before the Royal marriage between Diana and Charles in 1981, Camilla, now 77, was a romantic interest for the Prince in the 1970s, but their relationship ended as Camilla married Andrew Parker Bowles in 1973. Their union dissolved in 1995.

Yet, it's said that the Duchess of Cornwall and then-Prince Charles resumed their affair in 1986 - which prompted heartbreak and confusion for Diana.

"'I know he is seeing Camilla again. Am I expected to accept that, like the other Princesses of Wales before, one just turns a blind eye to husbands having a mistress! '" Allan penned as she remembered an emotionally charged confession from Diana.

"'Why does he not love me? I really don't understand. I have tried everything, tried to conform to his wishes even though I don't always agree. There's no affection between us, and I am always on my own. I just want to be loved. I can't keep going on like this. They are really expecting me to just say nothing and keep going. How do I do that? '".

After enduring years of marital turbulence, in 1992 Charles and Diana resolved to part ways and formalised their divorce four years afterwards. Notwithstanding the end of her marriage, Diana remained resolute about keeping sons Prince William and Harry at the forefront of all her decisions committing to hold her family "together".

Tragically, she passed away just a year after her divorce was finalised.