The whole thing is still very very new and you are both still in the very early stages of adjusting. There's no denying that a baby puts a strain on even the strongest relationship but it's a shock when it happens.
There's a couple of different things going on which seem to be quite common in your situation
Firstly blokes aren't generally great with new babies - it takes them longer to bond because they haven't been carrying them for nine months and when the baby finally does become a reality for them it is, to be fair, not the most pleasant of realities; it can seem exhausting, pointless, thankless and all that crying for what seems like no reason (and that's just mum!)
It often takes until about 6 months before the bloke gets the point of his baby; when they start interacting back and smiling and playing etc. My DP is getting better and better with our 10 month old DS all the time. At first he had less patience with him than I would have expected and he seemed to find the newborn stage quite difficult.
Then there is the fact that he probably feels left out because you and baby are cocooned with the breast feeding thing and you might think "grow up" but he can't help his feelings. the only advice I can give here is to make him feel as involved as possible, make him feel important and as if there are things that you really value his input on - even if its just buying things for the baby.
this difficult stage really starts to ease off after the 12 week mark and gets easier again from 6 months on. So you can offer him assurances that, much as he might think so, it is not going to be like this forever. It goes really fast and in a few months time he will be bemoaning the fact that she is growing up so fast!
Wherever you can try to make him feel included and try not to harbour any resentments but try to get him to pull his weight with bating, changing etc. She is his child too and you had to go through the hardest job of all in carrying her and giving birth to her. It doesn't hurt to remind himof that.
It is so easy to lose sight of who you both were before the baby came along. As soon as you can express some milk perhaps he could feed her the odd bottle? then you could have a bit of freedom as well.
then in a couple of months you might be able to get a babysitter and go out.
I know some women would find this a horrendous impostion on their feeding of the baby but I am not one of them. Your relationship needs to be nurtured alongside the baby and it is her best interests that you do so.
Tell him it will get easier very very soon and that he will fall in love with his daughter and the relationship between the three of you will be even better than what you had before.
as for the sex? 8 weeks is nothing! Give yourself a break on that one.