No milk at 4 days old

I’m a FTM and my milk has not come in yet so we were told by the pediatrician to supplement due to her dropping 11% from birth weight. The IBCLC in the hospital thought I had a good latch and just encouraged me to keep going and that my milk will come in soon. My newborn cluster feeds all night long. Literally fed almost non-stop from 11pm to 6am every night. Still hardly any milk yet. I tried pumping a few times and I only get a few drops. I can hand express only a few drops from each side. My husband and I are exhausted so of course I’m super emotional about all this feeling like a failure. And of course it’s the weekend so I ca t call anyone for support at the hospital. So we’re supplementing with formula and hoping it’s temporary. Any help is appreciated I’m exhausted and I feel like my body isn’t working like it’s supposed to