At our breaking point

Our daughter just turned one last week and has been a terrible sleeper since the beginning. Tons of wake ups throughout the night and daytime naps are very rarely more than 30 minutes. We’ve done the Ferber method a few times and have had success for a week or two each time, although all it takes is a cold or teething for her to completely forget how to sleep independently. I’ve also done crib hour for naps though it has yet to work.

We stopped breastfeeding two weeks ago hoping it would help her sleep longer throughout the night yet she’s still waking 4-5 times. Her wake windows are typically 3/3.5/4.

I can no longer function on a couple hours of sleep. She has only slept through the night 3 times since she was born. Am I just delaying the inevitable and should try CIO? Anyone else with success stories with a stubborn baby?