The Playboy model, who lost her unborn child last May, admitted that she had treated her boyfriend badly during her surprise pregnancy.
Giving candid details of the ordeal, she told Glamour: "We had our fair share of trials and tribulations with my pregnancy.
"My hormones were all over the place and I didn't know if I wanted to be in a relationship, because we'd just met. It's just the last thing you think about, having a family.
"And then all of a sudden you find yourself with someone you don't know that well, and you're in that situation. It was a beautiful thing, but a really scary thing, and I think we probably saw each other at our worst."
The 32-year-old went on: "I owe everything to him, really. I'd do anything for him - I was a monster at some points, because your hormones are all over the place.
"It's bad enough when women have that time of the month, let alone going through that. I guess we're kind of lucky that we got to know each other on that level so quickly."
Looking to the future, Brook added: "We've just had such a stressful year. We're happy to take a bit of a breather, work on our projects and spend time together doing fun things.
"We never really had that opportunity when we first met - I was pregnant, that was it. So at the moment we're being spontaneous, loving our new place and going shopping for cute things for our house. Just being a normal couple, really."
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