Don't feel bad, I have a 9mo old boy w/ severe reflux (and various allergy issues) and we still swaddle his arms and use a sheet tucked into and wrapped around the crib mattress to keep him on his back. If he manages to flip over he ends up throwing up. Both my pediatrician and gastroenterologist are fine w/ this. To swaddle his arms I use those swaddle blankets from the hospital...they seem to stretch more and be able to be wrapped tighter than new ones. I too am worried/wondering how to get him out of the swaddle eventually when his reflux eases up b/c it seems to be the only way he will fall asleep and stay asleep as well. A friend of mine said with her son that they started breaking the swaddle by only swaddling one arm. Maybe give that a try.
My sisters 5 month old still wants to be swaddled and she is using something called the miracle swaddle blanket. I think if you google it, you will find out about it online.
Anyway, all of my sons docs have said many kids like to be swaddled up until 1 yr. At which point they said to just slowly loosen it at night and they will adjust on their own to not having it.