My newborn keeps vomiting?

My 8 day old baby keeps being sick. He is being breast fed and sometimes it's just small amounts which i know is quite normal but most of the time its large amounts of sick asnd sometimes it is curdled and smelly. He has difficulty bringing up wind and retches after every feed like he might vomit. He gets hiccups a lot and sometimes pulls off the nipple and grimaces and cries like he is in pain. He's my third baby and I didn't experience this with my other two so I'm quite worried about him.