Kristin Cavallari says splitting from Jay Cutler was the ''hardest decision'' she's ever made.

The 'Very Cavallari' star revealed she had filed for divorce from Jay in April this year after almost seven years of marriage, and has now said the former couple ''tried really hard'' to make their romance work before deciding to call it quits.

She explained: ''It didn't happen overnight. We tried really, really hard for years and years. It was the hardest decision I've ever made. ... I still care so much about him and talk to him almost everyday.''

Kristin - who has Camden, eight, Jaxon, six, and Saylor, four, with Jay - also admitted the pair began to fall out of love with each other when they ''grew up'', and insisted she's ultimately ''proud'' of herself for making the right decision for her future.

She added to People magazine: ''When you work at something for so many years and nothing's changing, I think you have to just make a decision. We all want to be happy.

''A year ago I felt like I was drowning. I'm proud for making this decision. ... I feel like my whole world is opening up now because of it, and I'm just feeling the best I've felt in a really long time.''

The pair's joint custody agreement took effect in May this year, with their children spending 182.5 days a year with each parent.

Meanwhile, Kristin, 33, recently said she wants to ''better'' herself amid her divorce from the 37-year-old former football player.

She said: ''This is the first time in a very long time that I feel like I can take a breath. I'm enjoying things slowed down and having more time to focus on what really matters in life.

''I want to take this extra time I have right now to better myself and be the best mom I can be and continue to grow Uncommon James. I'm not thinking about what I want to be doing next year or the year after that. I've driven myself crazy with that mentality the past few years. Right now, I just want to be present and enjoy this journey.''