There's still a lot more learning to do. I personally dont think you realize how big of an impact it has on him. He was told by a medical professional to do something. This is what your life is based on. When a medical person says "You've got a deep cut, you better get stitches", you think "Well fuck yeah, I need them like now". Likewise, when a doctor says "You now have an STD - you need treatment and your partner should get treated too", you think "Fuck yeah, I need to get on that"

Your partner just entered a world where - that same person gets to say "Oops, I know I told you to tell your partner to do this, but hey! Mistakes happen. Better luck next time".

That's.. likely got to be beyond chilling. If I'm honest, his reaction, while over the top, is what was advised from both the medical profession as well as the very people you sought advice from. Do not doubt that these very people would be instant in telling him "She cheated" or "She didn't disclose information" if he had come to us saying "I've just been informed I have an STD, and I haven't seen anyone except my partner of 2 months"

The responses are nothing but mindblowing. I know he hurt you in his words and actions. But. I hope you take a moment to step out of that hurt and look at things from a whole. Because both of you are hurting from it. You might want to help reinforce him that professional opinions, while fallible, are not bad advice. Less next time you both DO seek a professional for opinions (say, therapy, physiotherapy, financial), he's going to be all over the place with "Can I trust him? If so, is it safe to come to my partner?".

This whole situation was a bunch of suck. I wish you both the best with it.