My baby is so hungry at night

avienda44

My DD was born 5 weeks preterm so she was put on IV then formula.  We have made the transition to breast with the aid of a shield and we are slowly phasing that out as well.  The problem is she has this crazy appetite between the hours of 8pm-3am and I can't keep up.  I don't want to supplement right now but I am left no choice when I have nothing left in my breasts.  I have tried increasing my daily output to every 2 hours but that still isn't helping at night.  I am so tired and I cry every night about it.  What can I do?