12 month old terrible sleeper

Wakes up constantly throughout the night, needs to be rocked to sleep. Will not sleep in her crib and I’m not sure why. The second you put her down she loses it. Should I just let her cry? It Happens at least 5 times overnight and I am exhausted. I thought it was supposed to get easier as she got older. We room share so if I put her down on my bed she instantly goes to sleep, transfer to her crib she loses it. What should I do? She eats plenty during the day, I’ve taken her to the doctor to rule out ear infection, not sure what else we can try. She’s been rocked to sleep since birth and has severe acid reflux when she was younger that made it hard to do any type of sleep training