I feel horrible

Oh mama take your time to process what just happened and gather yourself. It can be so scary having to make sure a little human stays alive when it seems like their only mission is to off themselves. He’s going to be okay. Trust me. This is the first of many actual bad times you’ll have and it’s something I’m personally still learning to deal with too with two boys. Just know it was 100% not your fault. You were doing the best in the situation actually! u were aware of what was happening the whole time and was trying to prevent something that could’ve been so much worse! u were there and are still there making sure your boy is okay and he will be. Accidents happen and it’s no one’s fault. Amazing you for being such an attentive mom

Soooo let me rephrase this a little bit.
A mom protected her child and tried to ensure nothing bad happened to the child during unexpected circumstances. During this emergency that mom used everything she could to prevent child from having a choking issue. The item ended up being too small to choke on and child cried because they could read the room and it was overwhelming. Child would not be able to cry if choking. And mom did amazing. Great mom reflexes. Now the adrenaline has worn off and it’s emotions time. Let it out.

Listen to me. It is not your fault. Things like this happen and all you can do is learn and move on. You handled the situation amazingly and you have no reason to feel guilty. Take the time to process what happened and then give your baby a big cuddle. If he doesn't poop it out in 3 days go to the doctor (in case it got stuck) but if it was small enough for him to easily swallow I very much doubt that will happen!!