Normal gestation is 37-41 weeks, so a baby born at 37 weeks isn't really born early enough to make a difference.
It's pretty normal for babies under 6 weeks old to be be very sleepy & many do just "sleep, feed & poop" & repeat.
In the early weeks the idea of EASY is really that they don't fall asleep when feeding, so a nappy/diaper change after feeding & then help to sleep,
The reason that she may act hungry after being fed is that 4 weeks is a time for a growth spurt & in breast fed babies they want to feed more.
In terms of night & day mixed up, keep trying to get awake time in the day and lots of direct daylight/sunlight if you can. Then at night try to feed in the dark and no stimulation, just feed & sleep, only change nappy if they are dirty or very wet.