newborn won't stop crying ??

Hey ladies I have a three day old baby girl, I'm breastfeeding her and try to feed her as much as possible. I know newborns are fussy but are they really THIS fussy? I fed my baby this morning and she ate quite a lot and took a two hour nap, I came home from the hospital and she was sleeping all throughout the car ride home, then I get home and she starts crying and I start feeding her. I burp her and then lay her down, she starts crying  and will not stop crying. I changed her diaper, fed her more, swaddled her, rocked her but she keeps crying. I notice everytime she's crying and I pick her up she stops crying but I don't want to get her used to napping on arms all the time. I keep feeding her, switching sides every now and then and continue for about 2 hours. This whole time she is eating but as soon as I lay her she starts crying and won't stop. Why does she keep wanting to eat nonstop? I swear if it was up to her she'd be on my boob all day everyday.