PP depression

I'm about to be 5 weeks pp tomorrow and I have no connection with my baby at all! I'm constantly crying and not knowing why. I feel like a bad mother. My fiancé went on vacation for the week and a half and will be back tomorrow. This whole week all I wanted to do was honestly end my life. I've wanted to just drive off and leave my baby inside the house and I don't even want to be around her. I feel horrible for saying that but I honestly can't say I love her yes she's adorable but I'd be better off with giving her away. She was born a week early and two days before I gave birth I was talking to my fiancé about adoption and we could wait till we were stable and ready but he said he wouldn't allow it so I left it as that and I continue to bring it up to him but then again I don't want to just giver away his daughter. I haven't talked to my doctor yet but I think I will on my 6 week checkup. But how can I tell her I'm feeling depressed? I'm not really good with telling people stuff like that. Sorry this is long. Please no negative stuff.