breastfeeding and my baby still fussy and crying

Keneisha
Trying to figure out what's wrong with little man as he cry when am feeding him mainly at nights as if he's in some form of pain. Anyone else been through this my son is only 3 weeks old 
It make me sad cause because he cannot speak to express what's wrong n am here clueless as he give me sleepless nights hoping for the very best also during the day he sleep like and angel