Completely normal! You're in survival mode at the moment... you've been ill, had major surgery, your baby has been ill, you're sleep deprived, I guess you're also in a state of shock.
I write this whilst feeding my 9 week old, and for the first three/four weeks I seriously thought I'd made a terrible mistake. My baby felt so alien to me, the poor thing was wrinkly, spotty and looked like a little old man and I just didn't feel love for him.
Now, a few weeks on and I can feel a bond starting to grow. I can see he's beautiful, he smiles at me, laughs at me, I'm proud of him.
Things that helped were; getting as much rest as possible, talking to other new mums, talking to my hv, talking to my mum and oh, skin to skin, lazy time on the sofa together, and as fickle as it sounds... buying him some new clothes and toys.
Hang in there, your bond will come but as a pp mentions, keep an eye on it and speak to your hv if you have any concerns. They won't judge you, and will have seen it so many times before. If they see you'd like help, they'll offer it, they have all sorts of help up their sleeves but don't always offer unless asked.