Strahan and Nation fell in love on The Bachelor in 2016, but called it quits after weeks of speculation earlier this year.
The single mum has since found love with Maegan Luxa, and the couple are reportedly engaged.
Now, Strahan has opened up about the break up.
“The months leading up to it were the most difficult, crazy and confusing time I’ve been put through," he told New Idea.
"Having something dissolve the way it did was heartbreaking, but at the same time, there was a lot of relief that the emotional rollercoaster was finally over."
Strahan revealed that the couple had made bad decisions which led to the breakdown of their relationship.
“I guess the brightest spark can fizzle fast. We made some bad choices back in June and our relationship really struggled to recover for months after that," he said. "It didn’t matter how much effort I put into it — sometimes these things are destined to fail.”
Although Strahan has not publicly moved on, Nation has been happily sharing photos with her new love.
"When it comes to love, my friends and family would tell you that my heart isn't one to discriminate," she said of her relationship with Luxa. "I very much fall for a person and the connection that I share with them."