as you probably read in pinkys book(s), around the six week mark there is a major growth spurt, and babies in general seem to get a lot more unsettled at this time.

Firstly, he actually just won't go to sleep and i mean literally!! He might be awake for 5-6 hrs at a stretch during the day.
I guess it doesn't help you to hear that this can be quite normal. I can vividly remember the day Milo was awake for 13 hours @ 6 or 7 weeks old.

Good luck, I hope you find something that helps you.