Baby Daddy Drama

Ok so I broke up with him because he was very selfish and immature. I'm trying to get help from the state before my baby is born but they want to know the paternity presumably to go after child support. I let the father know just to be courteous that they were probably going to go after child support. Now he is all upset in a tiffy. He wamts half custody when baby is born but until then legal custody is considered mine. Am I being selfish by getting help even though itll be a financial burden on the father. He seems to think so because Im the one who chose to leave.