Tasha,
You've received some fantastic advice, but above all the consistent message here is that your baby girl is normal. Totally normal. The sleep deprivation you are suffering, is unfortunately normal too. Peanutter's post is spot on. Sleep when you baby does - night and day. Focus on eating, sleeping and your baby. The rest waits, and if your DH or anyone else isn't happy with that then hand them the tea towel, duster or vacuum cleaner. And just as Peanutter has suggested, I'd like to also gently say go and talk to someone, hopefully a caring GP. I too have wondered about PND, or at the least, anxiety. There are people who can help you Tasha. Take care xx