I had a wonderful pregnancy and birth and acknowledge that I was very lucky. I specifically remember sitting in a pub garden with my husband when baby was 1 week old and saying to each other that we've got really lucky and we're bossing this. Then a few days later the low hit, baby stopped sleeping, developed colic, and it took me a good 9 months to feel like I wasn't depressed. And yes Meg, I had intrusive thoughts of throwing my baby down the stairs!
Hopefully this doesn't happen to Meg, but I do thing you need to be cognisant that this is very early days and you're still riding high on the birth hormones. I also think it's only fair to acknowledge what an element of luck plays into your birth experience. You can do everything Meg did, and end up with an emergency c section. Birth is not a competition and trying hard does not always lead to the best outcome.