Need help sleeping!

ChrMoo

My LO is three weeks old and we've been struggling with the sleep schedule. She does not seem to sleep as much as I have been told a newborn will sleep. To make matters worse she's not a very good night sleeper. On average she will have one sleep session of around 3-4 hours then she's up every hour to hour and a half after that till mid morning when she'll take a good nap 2-3 hours usually. This pattern is killing me how do I get her to sleep better at night? She's breast and bottle fed. She's not colic she just seems to like cat naps more than the longer ones. Has this ever happened to someone else? Please help me!!!!