A few hours after that I had what seems like a migraine aura without the pain. It started with a blurry blind spot in the center of my vision which then spread into a colorful zigzag line
Have you been to a migraine specialist yet? Some neurologists are knowledgeable about migraines and its worth it to try to find one.
The pathology of migraines seems to involve vasoconstriction of the arteries that supply the brain, and this can result in various symptoms that you report. Medications to treat "vasospasm" such as calcium channel blockers (e.g. Verapamil) can treat this type of condition.
A common cause of eye pain is due to constriction of the arteries that supply the muscles
(and I suppose nerves) of the eyes. This is common in migraine patients and it seems migraine visual symptoms and some "physical" eye problems overlap for issues related to this vasoconstriction problem.
An opthamologist once told me that rather than HPPD I likely had "acephalgic migraine" AKA ocular migraine, which he said is typically due to an artery spasming in the back of the head.
There is a (Swedish?) author who wrote about a Vascular Dysregulation Syndrome/Flammer Syndrome which mainly concerned various eye conditions, but also things like overly sensitive vasoconstrictive response to stress, which you seem to describe as well and I think other people experience. That author liked to treat that syndrome with calcium channel blockers as well.
For what its worth, I've had a couple concussions and my visuals were reminiscent of those I experienced while I've had a concussion, and part of the cause of the visual disturbances with head injury seems to be due to vasoconstriction