Kate Ferdinand "cried every single day for a year" when she first moved in with her husband Rio Ferdinand.
The 28-year-old author married Rio last year, four years after he tragically lost his first wife, Rebecca Ellison to breast cancer in 2015.
And Kate has now said she struggled to be the "perfect" wife to the former football star when they first tied the knot, and found it difficult to be a supportive stepmother to Rio and Rebecca's children, Lorenz, 13, Tate, 11, and Tia, eight.
She said: "I cried every single day for a year when I first moved in with Rio.
"It was an incredibly difficult time because his mum Janice passed away [of cancer in 2017] just two years after they had lost Rebecca.
"My heart was breaking for them. All I wanted to do was try to fix him, make the kids happy and be as kind and supportive as I could. I gave up my job. I wanted to do everything right. But I didn't know how to cook.
"I kept getting things wrong, like forgetting to put a gym kit in a school bag or missing an email from one of the kids' teachers."
Kate says she "lost" herself during the difficult time, and didn't want to speak to Rio about her struggles because she felt she was "moaning" when he "had much bigger problems to deal with".
She added to The Mail on Sunday's You magazine: "I would get into a total state because I felt I was messing up in front of so many people who didn't want me there. I wasn't a mum. I wasn't really used to being around kids, but I knew I would do anything for them.
"I lost myself. I felt as though I was acting all the time, trying to smile and learn to cook and be this perfect woman. I tried to talk to Rio but it sounded like I was moaning when he had much bigger problems to deal with. So I'd go to our bedroom and cry."