My 5 weekk old baby is always hungry irritable and sick after her feeds?

my daughter is 5 weeks old and is always hungry,irritable and is sick after every feed. she brings up most her milk which explains why she is always hungry,but she is wanting fed every 2 hours. she is on formula and taking 5ounces. some times when she is sick its with allot of force(projectile) can any one help who's been through this before..............thanks