Personally, I am not looking forward to the first few months. I have a feeling I will be right there with you and, YES, it is totally normal. I have TONS of friends who have said the same thing and warned me how tough the first few months are.
I totally know what you mean about how hard we all worked to get here and that adding to guilt about not being over-the-moon about every poopy diaper, I feel the same way about not loving every moment of pregnancy, since I know so many who would kill to be in my spot, problems and all. But, on the other hand, maybe we have added expectations after all the years of waiting that add to the feeling, you know? When you dream of something so long and so hard it is difficult to know how to feel about the realities.
But, if you are anything like me (and I think you are!) I still appreciate all the moments, good and bad. I am still in awe and grateful for all of it, but that does not mean I like every moment!
I think PP is so right (and I have head it from others as well) that this is the hard time, so much work, so little sleep. I bet it will get better.
Still, everything in your life, everything, has changed. You have every right to feel that, acknowledge it and gripe about it! No worries, I think everyone, no matter where we are, will understand that!
Hang in there, see if someone can watch her for a bit and take your DH on a date! A summer movie and some bad dinner can go a long way!