D.M.
You are an awesome Mommy!
Please don't think what you're doing is wrong...no matter what anyone says. It is completly natural to nuture and feed your child when they need it.
You haven't spoiled him by rocking him to sleep, you have done what is completely natural for a mother and child. I did this with my little dude, and he now sleeps on his own at 2.5 and falls asleep on his own...but, some nights he needs Mom's extra comfort and I'm totally there for him. It's about creating a bond between you and your baby, and it's the most amazing thing when you see it in their eyes at different moments that they KNOW you are the person they can turn to if they NEED something.
The CIO method is severe, and at this point in time there is tons of research that shows it releases a chemical in the brain that can be very harmful to emotional development.
At some point, you will want to transition, but it needs to be something you do as a TEAM. I use that term a lot with my son, and it's true. Working together with your child and help him understand what you are doing together.
What I did when we started to transition away from Mommy being the comfort to sleep at about 13 months, I think, was introduced a 'lovey'. It can be stuffed animal, blanket or something soft and cuddly. I would rock my son to sleep holding it in between us, and then once he was fast asleep put him on the bed with his lovey. He would wake and look for me, and for the first few weeks I would pick him up if he needed me to and rock him to sleep. Otherwise, over a few weeks he began to resort to the 'lovey' as his source of comfort. He would only NEED Mommy cuddles on nights when he was teething, sick or just having a bad night with night terrors or the fear of the dark he developed a few months ago.
But, now at 2.5 his lovey is obselete and he sleeps on his own.
I think, the truth is that kids never really 'sleep through the night', there is always some kind of issue or stage/phase thing that happens to disrupt the calm in between those times.
Don't think of this in terms of 'training' your little one to sleep, think of it as teaching/guiding him through a NEW process. Babies weren't born with the instant understanding that things will change, and why change happens. They need love and guidance, and most importantly patience.
You ARE doing a GREAT job, and I say keep up the good work. If you are ready to transition it will take time, and effort. But, don't think of this in terms of cold turkey, it is SO painful and confusing for infants to be cut off from the source of love and comfort.
Best wishes to you and your little one!
D.