My 3 week old wants to nurse CONSTANTLY. Any help?

My son is 3 weeks old and wants to nurse all of the time. Sometimes he eats for an 1 1/2 to 2 hours at a time and others he'll eat for about 30 minutes but want to eat more in less than an hour. I just feel totally tied down and can't do anything. He screams and screams until I feed him again. He sleeps pretty well throughout the day and night , but sometimes he's awake within 15 minutes of putting him down wants to eat again. When he's like this only other people can hold him because he tries to nurse when I do. Anyway, I'm a new mom and am very frustrated. Is he overeating? Am I spoiling him by giving in? How can I stop being his pacifier? (He will NOT take a pacifier either)