It is a massive change! Make sure you have plenty of support and discuss this grief reaction with your midwife or doc as it could be you have a touch of post partum depression too.
You could be experiencing the baby blues. I was like that for about two weeks after giving birth. It was like I wanted him back in my belly. I would cry because I felt overwhelmed but I slowly came out of it. I did inform my Dr just in case it was a serious case of depression. I wish you luck mama!