pumping and nursing

Kay
Hi ladies. My baby is 5 days old and my books are engorged. It hurts so much and feel like my boob is gonna pop. I'm now trying to strike a balance between supply and demand and not over producing and causing more engorging. I'm a ftm and don't know the rules so do I fully feed on one boob and pump the other? Do I feed 50:50? My baby feeds every 4 hours and not sure how to go about it. 
Please help I'm a ftm