Lucy Witchard, of Leicester, said David Carroll, 35, told her he had leukaemia when they met in 2006 – they married in 2011 and have since divorced.
She said in 2015 her mother gave him £2,000 for treatment in the US after he said the cancer was terminal.
Carroll was given a suspended prison sentence for fraud at Leicester Magistrates’ Court last week.
Ms Witchard told the BBC the family became suspicious while Carroll was in the US – enjoying a holiday rather than receiving cancer treatment.
The 31-year-old said she confronted him on his return, but he went “ballistic” and tried to keep up the pretence.
“He even got a work colleague to call me pretending to be his doctor,” she said.
“I knew after that phone call that our marriage was over.”
Carroll later admitted he had lied about having leukaemia.
Ms Witchard said she still felt “incredibly hurt and angry”, as he “stole so much of my life”.