The 30-year-old actress, who had five-year-old daughter Matilda with the Brokeback Mountain star, said that she thinks it will be 'impossible' to have a better romance than the one that they shared.
She told The Times, 'That's the tough one. It's like nothing will ever be that whole again. You just want impossible things.
'I've had to get down on my hands and knees and sift through the muck and mud, and try to find little pearls, little nuggets of things that make sense.'
The 30-year-old, who is currently starring in Blue Valentine, said that she would like to meet someone new, but that she is alright on her own.
'When you've had love, you always, in a way, have it,' she said. 'I am single but either is fine with me. I'm used to being single. Would I like to be with someone? Yes, I would.'