Helppppp

What do you do when your LO is still hungry and you're boobs are tapped out??? I don't understand why this is happening. 😭 he ate at 5:30 and then again at 8 but he obviously didn't get enough because he is freaking out. He will take a pacifier but is sucking ferociously at it like he wants more. My boobs hurt and feel so flat right now. I am trying to stay hydrated and I just started taking my prenatal vitamins again (once my digestive system was working). He's 16 days old. I know he might be cluster feeding but I don't know how to help him. I just want him to sleep so I can build back up but I feel like he won't sleep without a full tummy. breastfeeding went so well the first few days and now it seems like my supply can't keep up with his demand and it's just super depressing.