Welcome to NeuroTalk.

At the very most, unless you hit your head on a solid object, you stopped at about 1 G horizontal force. It takes 60 to 80Gs to cause a concussion.
Using stopping distance and time calculating with good tires on dry pavement, it takes 5 seconds and 140 feet to stop from 35 mph and only generates 0.4 Gs.

If you have headaches from your last concussion, you likely suffered a upper neck injury. Those often cause headaches.

The whiplash of a sudden stop can strain a previously injured neck.

You could have triggered a sinus headache of fluid in your sinuses.

Your anxiety can also cause every symptom you are experiencing. The startle on needing to make a quick stop triggers anxiety.

You say "but I cannot shake the thought that I caused more irreparable damage."

What would change IF somebody told you that you did cause irreparable damage? How would worrying about it change your life for the better? What would you do differently moving forward?

I have seen this response after a concussion many, many times. The anxiety that can take over can change your life. I encourage you to get out of this thought pattern. It can take over your life. As another NT poster says, If you would not have been concerned about this event before your concussion, don't be concerned about this same event just because you have experienced a concussion.

btw, I've had over 14 concussions. There is plenty of life after concussions, IF YOU CHOOSE to move on.