Fixated on my mistake that endangered my son

FTM here, I made a huge stupid mistake today that endangered the life of my child, and I can’t stop fixating on it.

This morning, I went and visited a friend at her house for a couple hours — my baby was getting a little fussy so I put him in his convertible car seat/stroller and was slowly pushing the stroller back and forth to keep him happy and he had a blanket over his lap. My friend had to leave suddenly so I was scrambling trying to gather together all of his and my stuff and somehow I completely spaced that I hadn’t buckled him into the car seat/stroller yet when I clicked his car seat into the base.

I only realized 7 minutes into driving that my baby was unbuckled in his car seat!! I immediately pulled over and strapped him in, and started balling thinking about what could have happened.

It’s been 12 hours and I still feel sick to my stomach and can’t sleep. I keep picturing all of the horrible ways my baby could’ve been injured or worse. I’ve been crying and holding him tightly, trying to shake all of the gruesome images in my mind.

Has anyone ever dealt with anything similar? I dont know how to manage all of these overwhelming feelings of guilt, shame, and fear from such an idiotic mistake.