Speaking to Men's Health, the model spoke about his 10-month relationship with The Saturdays singer, which came to an end in February.
"My perfectionism can make it difficult," he told the magazine. "I know my ex-girlfriend struggled. Things have to be perfect - everything in the house, every car I buy. That's incredibly hard to live with if you don't understand it."
However, Gandy said that he is enjoying being single again: "I can get on with my own life, my own 'perfections', without needing to explain that weirdness to someone else."
Focused on his career, the 32-year-old added: "If either a relationship or my work must suffer, then I'm afraid it has to be the relationship.
Gandy also admitted that he is very "self-critical" of his appearance, adding: "I hate my hair, my lips, my nose. And I can't grow a full beard. People assume I think more of myself than I actually do."
The full interview appears in the June issue of Men's Health, on sale Thursday, May 3.
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