United Kingdom, May 21 -- Sheryl Crow found out her former fiance Lance Armstrong was dating a "really famous actress" as she battled cancer.

The 64-year-old singer has revealed her life imploded back in 2006 when she split from the cyclist in the same week she was diagnosed with breast cancer - and she then found out her former partner had already moved on.

During an appearance on The Bobbycast podcast, she explained: "I was engaged, I had three beautiful stepchildren, I wanted to have kids with this person [Armstrong].

"We split in the same week I got diagnosed with breast cancer, and I found out he was seeing a really famous actress. I went through about nine months of radiation and grieving and anger."

The If It Makes You Happy st...