7 weeks? Do they do much at that age? I can't even remember? Even if he does smile at you or anyone else, its probably because of wind or poo.
I don't really remember feeling loads of love for my daughter that early on, just the sense of responsibility to feed her, change her, make sure she's well looked after. Trust me, you won't get much feedback at this stage, just keep doing what you're doing.
Now my daughter is 2, sometimes the constant feedback gets a bit tiring! "Mummy, sing alphabet again", "Mummy, put blanket on and gimme a hug".
Oh yes, I also agree with Molly, you and him are the same person in his eyes, thats a good thing, make the most of it while it lasts.
And being a first-time mum takes ALOT of getting used to, its like your whole identity has changed, you might not feel like a mum for a long time. Don't worry, its not you, loads of people feel like that.