I have a cautionary tale for moms of babies with serious sleep issues. You might feel like CIO is wrong and you keep putting it off. You might dabble in it a few times and then quit partway throughout because you feel it isn't working properly. You might find other sleep crutches to help you along and they'll work for a while and you'll think all is well. And then your sleep problems will worsen and you'll end up with a one year old who wants to nurse 5-6 times per night, who wakes after only 2-3 hours, who takes an hour or more to fall asleep at night and wakes up before 6 AM for the day even though he's still tired.
In my quest to be sensitive to my child's needs I became permissive to all of his wants too. Now I have to start over again. It's going to suck. I wanted to share this because it was very hard for me to distinguish which needs are most important. The need for a good nights sleep for you and your baby should be top priority. I focused a lot on his need to be close to me, maybe out of guilt from working, I don't know. What has resulted is exhaustion on all sides, and I feel like I'm worsening as a mom because I am so tired and becoming resentful.
Maybe if I had a child that was a bit more of a natural good sleeper the other more gentle interventions I've tried would have worked by now. I was so convinced that staying next to his crib until he fell asleep was going to keep working. In comparison at the time he slept longer after I stayed with him than when he was alone.
I am starting sleep training again tonight. I dont know for sure what will happen. All I am advocating right now is to do what is best for your family and don't forget to take care of yourself too. Mothers tend to feel like they are invincible to the needs of human beings so long as their child is happy. But we are humab too. I don't think I reminded myself of that enough over the past year.