I did the same thing with my first 2. I started it for the same reason as well. My middle son had lots of ear infections and didn't sleep well in his crib. I was able to transition them back to the crib w/out much fuss. Try warming the crib first like with a heating pad or hot water bottle. This way there's no shock when they hit the cold mattress. I have the Fish aquarium by fisher price attached to the crib and they really like that, so if they woke up, I would turn on the fish. I did let them cry for a bit and go back and reassure them that I was there. Your l/o is used to having help falling asleep, so it's a bit tough to get them to switch to doing it solo without the swings help. Good luck!