Postpartum depression

When does postpartum depression end? I'm supposed to go back to work next week but my body physically hurts, I don't feel connected to anyone and I can't even get out of bed. I feel like I made this child and that was all I was meant for. There's no reason for me anymore. My body grew the baby and now I'm empty. It really sucks and I just want to go back to when I was happy but this time be happy with my new family.