Sandra Bullock admits she was blindsided by ex-husband's infidelity.

The 'Gravity' actress, who has a three-year-old son Louis, whom she adopted in 2010 shortly after her split from motorcycle mogul Jessie James, admits it took her a long time to get over the fact he cheated on her multiple times.

She told the UK's Daily Mirror newspaper: ''I've been on the floor and I've been heartbroken. I didn't know how I was going to stand up. But I just gave it time.

''You don't think it will pass when you're in the middle of it, but it does. I'm so lucky to have what I have. I have a beautiful child and friends and family I adore.''

The Oscar-winning actress credits Louis for helping her to look at the world differently and giving her a new sense of perspective.

She said: ''I was OK about being alone but when you have a child everything is about exploration and being around other kids and being out in the world and seeing things.

''So now I see things through his eyes. I haven't ever gone out and explored and done things before like I have in the last three years.

''I have the best life right now because I'm enjoying every single moment of this amazing human being. I'm learning how to have a good time through him... I've got everything I want, and it couldn't be sweeter, better or more fulfilling.''