What a horrible experience

It's your choice, really, I don't get why your parenting choices bother other people that much. Why should you have to justify yourself to get them to sign that form. All you should have to say is that you are aware of the risks, you researched it and you have decided against vaxing. Your actual reasons, are really none of their business. They just need to know that you understand the decision you are making. It should not ever have become a debate - or a test of your knowledge on the situation.

I am so sorry you went through that