Jessica Simpson gets withdrawal symptoms when she's not breastfeeding her daughter.

The singer-and-actress gave birth to little Maxwell Drew on May 1 and while she is nursing her most of the time, she admits she finds it hard when fiance Eric Johnson feeds the tot.

She said: ''It's become a full-on job. It's the worst if I have to pump and give Eric a bottle to give her. I miss holding her and having that closeness.''

Since becoming parents, Jessica admits her and Eric's lives have changed completely.

''Life has completely changed. From how I sleep to what I think about, Maxwell has definitely taken over everything!

''We stare at her all the time. We can't get enough,'' she told People magazine (www.people.com/people/article/0,,20599227,00.html).

After 9lb 13oz Maxwell was born, Jessica announced the happy news on her official website, saying: ''We are so grateful for all of the love, support and prayers we have received. This has been the greatest experience of our lives!''

She later tweeted: ''I am so in love with baby Maxwell. I want to cry every time I look at her. Motherhood is by far the best thing I've ever experienced.''