I don't know how you feel about the Bible, OP, but here's this for you:
King James Bible (Cambridge Ed.)
As arrows are in the hand of a mighty man; so are children of the youth. Psalm 127:4
What you're going through at this moment is normal. Most parents, at any age, no matter how baddly they want to be parents, usually have an "Oh shit!" moment at first. It's just that this is suddenly real; having a child is no longer something you want to do someday, it's something you're going to do someday SOON.
Take comfort in the fact that no matter what, you'll never be ready! If you had a great house, all your needs met, and million in the bank, you still wouldn't be ready!
It's not easy. In some ways, it's the toughest thing in the world. But by FAR, it's the most rewarding, most worth while, most amazing thing I've ever done. For me, at least, being a parent is worth every single other thing. Any could haves or woud haves pale and fall appart when I think that I'd have had to have traded in being a mother to my awsome boy. Really.
And as we've talked about quite a bit in other threads, kids need love and kids need you. And the great thin about kids is that YOU and YOUR LOVE trully are the things they desire most in the world! All the rest is gravey and if you were to ask someone else's kid, some kid who seems to have it all, I bet they'd tell you in a heart beat that they'd trade everything they have if they had to, just to be with their parents.