The 28-year-old appeared in court last month to give evidence against former friend Rachel Taylor, who was jailed for 16 months for her crimes.
It is claimed that Rachel, 54, convinced X Factor star Rebecca to allow her to control her finances – leaving shy Rebecca now unable to trust at all.
Speaking to the Mirror, Rebecca said: “I finally got justice, but I’m still recovering from it all.
“I opened myself up to people I thought really cared about me and, when I look back, I realise I was naive, trusting and young.
“I’m one of these people who tries to look for the good in people, but I’ve learnt that, actually, no, some people fundamentally just are not nice.”
Rebecca – who is a single mother to her three children – is believed to have put aside a large sum for a trust fund, which Rachel shamelessly stole from her.
Rachel pleaded guilty to two counts of fraud, and the judge said: “"In the court's judgement you sought to exercise unscrupulous control and influence over your victim, Rebecca Ferguson.
"You were initially a friend of hers but the court is quite satisfied that thereafter you sought to trade on her success as a songwriter and singer."
Despite everything she’s been through, Rebecca insists she’s not looking for sympathy.
She added: ““A lot of negative stuff has happened to me – that’s why I’m tough – but I don’t want people to be like, ‘Oh, poor Becky’, because I’m not a victim.
“It’s a lesson learned and I’m a better, stronger woman for it.”