The worst moment of my life, BAR NONE!

Today, we had the sliding door open so the breeze could come through the screen door. Kalan discovered how to open that today. As I was going for him, Kaiden came to the rescue, as he was right next to him, and he picked him up and sat him down. The rest is the worst moments of my life:
So, Kaiden sat Kalan down and he had picked him up as a reverse bear hug type of hold. He is always picking him up...not anymore.... So as he sat him down, Kalan started to cry, he then crawled to me, crying more and more. I picked him up and he started crying even harder, then he started to gasp for air and then his eyes rolled back in his head, he went completely limp and began to turn blue!! I thought he was choking! I did the 5 back blows to the back, between the shoulder blades and then turn him over to check/begin compressions. PRAISE THE LORD, he came to. He started to just pick up where he left off with his crying then stopped, and just looked around so confused. I was so scared, crying freaking out!! WHAT JUST HAPPENED?? All I could think was him just going limp and blue! I waited a few, as the ambulance was almost here, and then tried to get him to stand, he attempted but his knees kept buckling. Then the EMT's said that he just had the air knocked out of him??? But that's instantaneous. We sent them on their way and took him to the ER ourselves, because by this time, 20 min after, he was playing and acting absolutely normal! They said that although they can't rule out Seizure, they think he had a vagal response. Basically he fainted. But he was screaming like he was in pain and then had a post episode of confusion and weakness. Our friend Tammy is a doctor, she said she thinks it was a seizure also. They are sadly a bit common in children and but usually have no more incidences. I'm hoping that it was just a one time deal. All I know is my nerves are shot and I'm dying!! We go to our doc tomorrow at 1pm to see a plan of what to do!! PLEASE PLEASE PRAY FOR HIM AND US! GOD WAS WITH US THE WHOLE TIME! But I just can't reitterate to everyone how insanely scary it is to have your baby have their eyes roll back in their head, stop breathing, and turn blue. I would HIGHLY reccomend to everyone to get CPR certified asap or at least look up/teach yourself the techniques.