The rocker split from the No Doubt star, who is the mother of his three sons Kingston, Zuma, and Apollo, in 2015 after nearly 20 years together and 13 years of marriage. Their divorce was finalised in April (16).

Gavin told Fabulous magazine he still thinks Stefani is "incredible", and never imagined their relationship would end in divorce.

“It was a lovely 20 years and we have three amazing children. There were a lot of positives and with time they’ll become more and more obvious," he said. "(Divorce) was completely the opposite to what I wanted... But here we are. Apart from death, I think divorce is one of the hardest, most painful things to go through.

"The only good thing... is we care about the children and it's about them, so we do everything to make this life change as seamless as possible," he explained.

Admitting the split came as a shock, Gavin revealed he struggled at first: "For me, it was about being solid for them (kids) and silent and respectful of Gwen," he said. "That’s what I’ll be forever. Those days were the worst days ever; it’s all a bit of a blur.

The 51-year-old is currently a judge on the U.K. version of The Voice, a spin-off version of the U.S. the talent show which featured Gwen shortly after their split, and Gavin was full of praise for his former wife's role on the programme.

"She's so incredible at it," he added. "She's really, really brilliant at that show. She's so natural at it. I hope that I'm just half as good as her."

After their split, Gwen, 47, went on to find love with her fellow The Voice judge, singer Blake Shelton.