A: We all experience "oops!" moments like this as parents. I know it feels terrible, and I've been there myself. Once I was helping our daughter navigate her way to the potty late at night and I didn't catch her soon enough as she fell -- face first -- to the tile floor of the bathroom. I still cringe when I think of it.
It's not that there shouldn't be parenting mistakes. Rather, it's how we deal with them. It's important to know that kids are resilient and flexible, and they take their cues from us. If your son senses that you feel horrible, HE will start to absorb your feelings about the incident. On the other hand, if you apologize, give hugs and kisses, and then move on -- he is likely to move on, too.
However, if you find that you just can't shake your guilty feelings, I'd be concerned about symptoms of depression. If your feelings last more than a couple of weeks and interfere with your enjoyment of your child and your life, please reach out to a trusted doctor, nurse, or counselor to ask for a referral for a qualified therapist who can evaluate and treat depression. Therapy WORKS!