The Aston Villa defender deputised for Harry Maguire in England’s first two games against Croatia and Scotland, with the latter still recovering from an ankle injury.
Mings, quoted in the Sun, said: “I did have a tough time in the lead-up to the opening game against Croatia.
“I think I’m a lot more hardened to outside influences now, but my mental health did plummet. And I have no shame in admitting that because there was so many unknowns about me going to that game.
“I was probably the only name on the teamsheet that people thought, ‘Not sure about him’. And that was something I had to overcome. When 90-95 per cent of your country are having doubts over you, it’s very difficult to stop this intruding on your own thoughts.
“So I did a lot of work on that with my psychologist. It was hard. I didn’t really sleep very well before that first game.”
American gymnastics star Simone Biles has made headlines at the Olympics by pulling out of several events due to a mental health issue, while England all-rounder Ben Stokes is taking an indefinite break from cricket to safeguard his wellbeing.
Mings, 28, said: “It’s just great that we are playing in a time now when you can speak about mental health, and how you are feeling.
“We have seen with Simone Biles you can speak on how you are feeling and hopefully feel supported by many people.”
Former England defender Rio Ferdinand was a notable voice questioning Mings, in his role as a BBC pundit, but later contacted the Villa star to praise both his performances and his response to home secretary Priti Patel’s dismissal of England taking the knee as “gesture politics”.
When Patel tweeted her “disgust” at online abuse of Marcus Rashford, Jadon Sancho and Bukayo Saka after their penalty shoot-out misses in the final, Mings wrote: “You don’t get to stoke the fire at the beginning of the tournament by labelling our anti-racism message as ‘Gesture Politics’ & then pretend to be disgusted when the very thing we’re campaigning against, happens.”
He said: “Rio DM’d me after the tournament. He’d said I was the weak link, and that Croatia should be targeting me.
“He messaged me saying something like, ‘Top-class response — matched your performances on the pitch.’ What a lovely guy.