Lurking....I'm going to third that "Healthy Sleep Habits, Healthy Child" book. I read the whole thing in just a couple of days I was so desperate with DS1, and when we finally implemented it, it was great! DS1 was exactly like you described your DS. Never slept, and when he did it was never longer than 2 hours, and only if we held him! It was awful.....but it was only when I recently had my second DS that I realized what we went through with DS1 wasn't normal. Something just wasn't right, be it colic, or reflux, or whatever it was.
The book helped me understand the biology of sleep. I believe, in the book, it explains that most babies don't start sleeping through the night until around 6 weeks at the earliest, because of the hormone 'melatonin' finally kicking in. Of course, this also helps in daytime sleep as well. The hormone helps us to fall, and stay asleep. So, there may be hope for you around the 6 weeks mark. But if not then, the book also describes the 3-4 month range as being a magical time for a baby to start sleeping better. That was the case for us with DS1. It was like a switch was flipped over night and he just started sleeping better. It wasn't perfect, but it was better. He'd sleep 3 hours out of our arms, instead of just 2 in our arms.....and it just got better from there. It was interesting too, b/c at the same time as this, he did a lot of things better....like taking a bottle without refusing, and riding in the car without screaming. So, I'm just convinced it was something biological that just needed time to work itself out.
We did start CIO when he was around 6 months, and he became the best sleeper ever! He would sleep from 6:30 PM to 8:30AM. Plus wonderful naps!

Anyway, I say all of this to say that there is hope, and if it is just a biological hormone thing, it should get better really soon for you!

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