Honestly it sounds like one of those things that simply happens from physical stress. I get stuff like this sometimes if I have to do too much exertion in a really short time. Or if I have like a really bad coughing fit.
There's no reason to be scared. Part of the reason why it feels more intense to you is because you mentally focus on it. I have a tendancy to do that too, with "medical" things, including totally harmless stuff.
I can also get that weird disjointed aspect too. If I get one of my "headache but not really" things, I get a bit mentally lost until it goes away. Mostly the sensory aspect of it is just a bit too much. Despite that, it's harmless, and its been explained to me numerous times as to how it happens and what causes it. Doesnt stop it from driving me crazy.
Anyway, I will say though, if you're not in general, immediate danger, dont go to the ER, go see your usual doctor/physician instead. ER docs are mostly about dealing with really severe injuries or various sorts of health crisis. For a bit of head pain or sensory weirdness, yeah, just see a normal doc. That way you can rule out anything that's actually bad, and they might have advice for you on how to mitigate it in the future, which is very useful stuff to know.