dd2 is just over 4 weeks old and was incredibly sleepy for the first 2-3 weeks. She is becoming more wakeful now and feeding a bit better, ie not falling asleep so much. But the last 2 nights have been horrendous. She is cluster feeding for 3 or 4 hrs in the evening which I can deal with but she then wakes around 12 to 1am and will not settle for more than 15 mins until 4 or 5am. I can't sustain this as have dd1 to think about but have to spend part of the day catching up on sleep. At night, I switch her between breasts quite a lot and she feeds well for 3 mins or so then falls asleep, and repeat... I try to keep waking her a few times so that she feeds more and then even when she seems in a deep sleep, it's only for 10 or 15 mins! Please help, any tips?