Hi, sorry am crashing this thread, but couldn't help replying.
The best advice I got when my DS was a newborn, was to feed them until they are full everytime, because the more they eat the longer they will then go before the next feed. I aimed for at least 20 minutes, up to 40 minutes feeding time as he got a bit older. I kept him awake during a feed very gently with a few rubs on the back or foot, and a nappy change mid feed. At 2 weeks my DS was feeding pretty consistently every 4 hours.
I know this is really hard to do in the middle of the night, but a 3-4 hour sleep will make such a difference to you.
I also started a bedtime routine at 3 weeks with a feed, bath, feed and then put down to bed at 7pm. I know 3 weeks seems early, but I have done this consistently since then and now DS know exactly what to expect every night and falls asleep on his own pretty much as soon as he is put down. (well most nights anyway!)
Good Luck, it does get much easier and the weeks pass really quickly so enjoy it as much as you can.