The 34-year-old model discussed her split from Cooper, 45, and her new life as a single mother in the March issue of British Vogue.
Shayk and Cooper called it quits in June after four years of dating. Shayk said she's grateful for her relationship with Cooper, an actor who recently starred in A Star is Born, The Mule and Avengers: Endgame.
"I think in all good relationships you bring your best and your worst -- it's just the nature of a human being," Shayk said. "Two great people don't have to make a good couple."
"I think we've been very lucky to experience what we had with each other," she added. "Life without B is new ground."
Shayk and Cooper have a three-year-old daughter, Lea De Seine. Shayk said she's struggled since the split to balance her personal and professional life.
"It's hard to find a balance between being a single mom and being a working woman and provider. Trust me, there are days I wake up and I'm like, 'Oh my god, I don't know what to do, I'm falling apart,'" she said.
Shayk previously said in an interview with Harper's Bazaar that she believes women are capable of anything, including being a working mother.
"There is no real challenge," she said of motherhood. "I really believe if you love something, you can prioritize your time. [Motherhood] is just an addition to your life."
Shayk also stressed the importance of being her authentic self for her daughter.
"You have to be really truly yourself for your kids, otherwise you're living in a lie," she said.
In the British Vogue interview, Shayk described herself as having a "strong personality" that sometimes scares men.
"If somebody's out of my life, they're out of my life and I really cut all the ties, you know? I think some people are really scared of this coldness. I also think not many people know that underneath this there's a nice, sweet person who cries in interviews," she said.
Shayk is known for her modeling work with Sports Illustrated, Victoria's Secret, Burberry, Versace, Givenchy and L'Oreal.