Baby Blues and Postpartum Depression
It sounds like you are suffering from the baby blues or postpartum depression. The baby blue happens to many moms and it should last for more than two weeks. The symptoms of baby blues are generally mild, sadness, crying, irritability. If your symptoms last more than two weeks or become worse then you probably have postpartum depression.
The most important thing you can do for both is talk to someone you trust. Call a friend, family member or doctor for support. Honestly tell them what you are feeling so they can help you. Don't be ashamed, what is happening is common and you did nothing wrong.