So my son is 4 days old and I’m trying to only breastfeed but every time I feed him I get the “after…

So my son is 4 days old and I’m trying to only breastfeed but every time I feed him I get the “after pains” but they’re so excruciating that I literally cry and can hardly sleep because it hurts to lay down afterwards. Normal or not? If normal how long does it last because I’m tired of feeling like I was hit by a bus.