It's totally normal, whether PND or not - and it won't last forever. Though if you continue to feel bad, or even now - go have a chat with your GP and if you need some help to get through it then do what you need to do.
I felt very isolated and incapable when my DS was born and as the months wore on (ahem, after I was prescribed some mild anti-depressants) I found things easier to manage, and got into my own mothering groove. But in the beginning I was utterly defeated by the whole experience and convinced I was messing it up.
Having the right support is so important. If you're far from family then it only makes matters worse. Consider getting some outside help (not your MIL) to give you even a few hours a week to get out and about by yourself to reclaim some of your old self and don't be so hard on yourself.
You will have that great relationship with your DD that you envisaged, it will just take time.
my amazing DD is 7.5 weeks. I am feeling increasingly anxious about being alone with her as if I will do the wrong thing. not that I would harm her or anything like that, just in a not confident kind of way. I much prefer the weekend when DH is here.
some context - I have lived in Oz for almost 2 yrs DH is from here. so I have none of my family around. DHs parents are a bit hit and miss in terms of how much they want to be involved with DD. I do have contact with a small group of other mums who are local but it would be fair to say that my social circle is a bit limited.
I only started looking after LO by myself 4 weeks ago when my mum left so that could have set things back a bit in terms of how long I'm still feeling like this. but all I know is its getting worse not better.
yesterday I was falling apart and ready to talk about it, my DH sent his Mum around, who was the last person I needed to see, so now I've woken this morning and feel even worse again. I think we were unfair on DD to have her if we couldn't look after her. She is and was so wanted and loved, and now I feel terribly guilty.