post partum depression

I'm not sure what to do. I think I have PPD and I feel like a failure as a mother and a SO. My baby cries and cries and cries and nothing I do will make her stop. I snap at my SO over the tiniest things, all I can do is cry and blame myself for my babies unhappiness. I don't see my OB until the 24 for my check up and I'm not sure what to do until then.