OH MY GOODNESS!!! What an absolute nightmare for any parent. I am so, so, so glad he is ok and now is doing fine. It sounds like you did everything right.
To be honest, I have taken infant and child cpr classes, and have had cpr training all my life in swimming classes and through work, and have the booklets around, and the cards in my wallet, but I STILL wonder if I would do the right thing if my son (or anyone) was actually choking or stopped breathing! Hopefully my subconcious would take over and do what I've learned.