Depression during pregnancy

Is anyone else experiencing depression? I'm currently 27wks and I am so depressed. I feel like my whole life is taking a terrible turn. I'm not enjoying life, constantly crying, my husband and I keep getting into it, I just feel useless. I was a tad bit depressed with our first child but this one takes the cake. I'm always crying and feeling helpless and less loved. People think I'm exaggerating but I'm not, after today I just don't feel like living.