Fear is not a bad thing. Fear is a biological behavioral response that has assured the human races' survival for thousands of years. It's instinctual.
Logic can guide fear, or rather influence our response to fear. Do I fear AIDS? You betcha. But I have the logic and facts to make a calculated risk/benefit analysis and either overcome or mitigate that fear so that it does not control me. I know to avoid risk behaviors, but I still take part in normal life.
I have done a similar risk/benefit analysis for vaccines. I know my childrens' particular risks of contracting the diseases, and of having severe side effects of the illnesses. I also am able to consider my childrens' particular risks from the vaccines (based on family history, medical history of each individual child, etc) Do I fear pertussis? YES. I very much fear it for my middle son because of specific risk factors he has that my other two do not. BUT, as of today anyway, the risk/benefit analysis is still leaning towards not vaccinating.
As of today.
I say that again because it's important, I think, for every parent to continually re-evaluate their decisions, not just regarding vaccinating, but every aspect of parenting. Today, my children are breastfed, intact, and not-vaxed. Tomorrow any of those decisions may change if I am presented with logical fact-based evidence that changes the risk/benefit analysis.
In your case, your child was faced with an injury that concerned you. Whether we all agree with that concern is not the issue, YOU came to the conclusion that it was concerning, taking into account variables that we may not know. You reassessed the risks/benefits and came to a new conclusion. You did the right thing, for you, in that circumstance.
Having said that, you are by no means now a 100% provaxer! Or at least, you don't have to be. There are many selective vaxers out there, for good reason! Maybe you'll now get all of your children vaccinated with DTaP, maybe you won't unless another child has a similar injury. Either decision is okay as long as you evaluate it as logically as you can.
Fear is not bad, but do try to ensure that you let logic and facts guide your fear, whenever possible.
I think the OPs message is just a reminder that all of us should be revisiting our decisions regularly, to ensure that we are up-to-date on information available, to ensure that we have an idea of what circumstances may cause us to alter our course, to ensure that when faced with something that challenges our beliefs, we are able to make educated decisions. And also to remember that changing our decisions is not bad.