I'm lost...

I feel like an awful mother. My baby is 2 weeks and 3 days old and I love her so so so much. But at night when she won't sleep and she just keeps crying and I can't figure out what she wants I feel myself getting angry and annoyed with her. Then when I come to my senses and realize shes just a baby she can't help but to cry I start to cry because I feel awful for getting so upset with such a tiny little innocent being. I don't know what to do. I am just so tired but she's been having trouble pooping and will be up almost all night trying to poop. I wanted to be a mommy so badly and was so excited to have my baby after two miscarriages how can I possibly be this terrible at it?:(