Losing Jackson

I was riding a bike with my 22 month old son and daughter. I think my daughter was in a seat on the back but I was holding my son. I wasn't able to control the bike though so I put him to sit on the bar. I was surprised that he was able to stay there without falling off. But then I needed to stop and he ended up flying off the front.
I knew I needed to put them both in a seat on the back so I was scrambling around to get the seat set up. We were in a cafeteria sort of place so it was crowded with people. Jackson somehow got out of my sight and then I couldn't find him. I believe my mother was there so I left here with Madison as I ran out a door to see if I could find him. There was a stairwell and a door to outside. I ran up the stairs a bit screaming his name. I realized he wasn't up the stairs so I ran out the door to outside screaming his name mostly in the hopes that someone would hear me and help me find him. I was in such a panic that I would never see him again. I'm pretty sure I found him but I don't remember it specifically.