The 46-year-old "On The Floor" hitmaker split from the "My Baby You" singer in 2014 and says it was a "devastating and awful" time of her life, reported People magazine.
"It was devastating and awful. I think both Marc and I thought at the time we would be together for the next 40 years until we die," Lopez said.
"It was the biggest disappointment of my life so far. But I felt like at that time I had lost my way a little bit, of who I was in trying to make the marriage work.