sleep training?

My LO is horrible sleeper! We're 19 weeks old and up every 2hrs (often less!) at night. I don't even think I'd call it sleep regression because she's ALWAYS been like this at night. Since around 3 months she began only napping for 35 minutes at a time during the day too 😞. She is EBF. Has to be rocked to sleep and wakes up when she's put down in her crib most of the time, keeping this tired mama up trying to get her to sleep. My pedi told me she shouldn't be eating during the night anymore and to look into sleep training. Anybody have any tips that worked for you?! HELP!