Unhappy Baby

My baby is almost 4 weeks old and he just seems to be so unhappy, he is always grunting like he's trying to push out a poop or gas and he is spitting up constantly, his spit up has become more violent by the day, at first it was just here and there now it's all day long with every feeding and seems to make him upset when he does it. Has anyone else gone through this?! Can anyone help?! He's breastfed, no formula