OP I don't know what you think PND is- a failure, neglect, violence, being crazy, inability to function.
BUT all the feelings you mention- the emotional numbness, not able to meet your own needs, only looking after your baby, sound like mild PND to me.
These poorly feelings can be exasperated by lack of sleep.
Go to your GP and say that you don't feel like you've bonded, even though you are well able to care for her, and wonder if you have PND? She may well advise you that a lot of new mothers feel this way, especially if they have lack of sleep.
If you had a traumatic birth you may need to process it and some counselling and post birth de briefing may be what you need, so have a think about this and ask for it if you think it would benefit you.
Sometimes we consider ourselves as very stoical, whereas in fact we are just emotionally shut down. This may be the best opportunity in your life of learning how to live with emotions that you formally were able to repress and control.
If you're introverted you may find the constant presence of a babe too much to cope with in which case you need to recruit some help.
It's not easy asking for help if you're not used to doing it, but if you need more 'me time' to process what has happened to you, well, then , you HAVE to ask to get it.
I would start by asking the GP what she thought about your cold feelings.
Personally I think you're having a rebalance of hormones from having massive hormone levels in pregnancy to having a low level now your placenta is gone. Sometimes anti depressants bridge the gap between when your own body acclimatises to the low hormone levels and help you through the mummy trenches tunnels of the first few months campaign.
I would advise you go to your GP, DO NOT think of yourself as a failure, consider you've been through a very life altering experience, and are doing marvellously to have sought help her and you sound like a wonderful mummy.
The feeling of enjoying it will come with time, and until then, get all the help you can, and that includes talking with your GP and maybe going on anti depressants to bridge the gap.
Best of luck with it all, and keep posting!