Sleep help

Hello, My baby used to sleep 10 pm - 9 am. For about 2 months she has not been sleeping at all. We just started following taking cara babies 5 month schedule. Her bedtime is 9 pm . She wakes up probably every 2-3 hours. 2-3 am wide awake, 6 am wide awake, 7 am wide awake. Up for the day at 8 am. What are we doing wrong?? How do we get baby to sleep through the night. No we are not feeding through the night anymore. She takes a paci and goes back to sleep but the constant wake ups are killing us.