12 day old newborn is cranky at night

My 12 day old newborn does not really sleep much even during the day. At night we start to prepare her for bed at about 10pm after feeding her. I mix breast milk with formula as I have very Low supply. She will fall asleep for awhile and wakes up crying and then we will have to make her sleep again and this takes us up to 1-2 hrs because she just won’t sleep soundly and then she is hungry and cries for milk again and the whole process repeats through the night. I am so stressed. Is there something wrong with her ? #advicepls #1stimemom #firstbaby #pleasehelp