I felt exactly the same, in fact after DH's first day back I begged him not to go in the next day (he worked from the following day, which helped a lot).
Very soon after that DD and I got into our own routine, it took only a few days, and then it suddenly became so much easier.
There was a brief period a few weeks that I almost resented DH being home at the weekends as it messed up the lovely little routine that I had with DD (that mild resentment also passed really quickly).
I see early parenting as a complex project management task: you have deliverables (wash baby, feed baby, take baby somewhere, keep baby comfortable, keep baby engaged, keep self clean and fed). Once you've got those 'deliverables' locked-down you can start to relax and enjoy it a bit (usually about the same time as DC starts smiling).
It's natural to feel a bit disconnected, people talk about the baby blues hitting on day four, for me day ten was the worst (so day 13 is not too far off that).
I was suddenly overwhelmed with the thought that I'd ruined our lives, that I was irreparably changed, that it was permanent and terrible. That passed too.
If you feel like that for longer than a week or so, speak to your doctor (PND is not unusual and nothing to be ashamed of).
But give yourself a break, your whole world has changed, you're probably not sleeping v well, you've got a million new worries, your body is (temporarily) dilapidated and you've got more hormones rushing around than a teenage boy. You're bound to feel a bit rudderless.
Congratulations!! And good luck!