I don't think your events, even when prolonged, likely cause physiological damage. But, they do establish neural habits. You sound like you can get that laser focus on your symptoms with little provocation. Have you tried CBT (Cognitive Behavior Therapy) ?

Lamictal acts by enhancing GABA.

In my view, propranolol should not be taken as a maintenance drug unless you constantly have high BP which you don't. But, it is can be very effective as a rescue drug to settle things down. That is why having a BP home kit is important.

Regarding CBT, It could also be combined with some facts. Nausea and some of your other worst symptoms can be caused by anxiety and/or a concussion. But, if your nausea was caused by a concussion, it would be a sign that your brain had suffered a serious trauma and the other symptoms would make it so you would not be able to put such organized thoughts together as you have.

Concussion nausea would be combined with mental confusion and a reduced ability to focus cognitively.

Anxiety nausea would be combined with heightened focus on symptoms and a strong desire to understand them and an ability to communicate about those symptoms.

Word finding and similar struggles can be anxiety and even depression so they do not necessarily point to brain injury.

How much time do you spend each day online or with a smart phone ?

What can you do to be active in ways that distract your mind ?