i think i had an experience similar to yours, but i'd been smoking for about half a year before it happened. i was at my friend's apt smoking a couple j's (weed was some good mids, but nothing especially potent) and afterwards we went outside into the living room. as soon as i walked out the room started spinning, and i saw bright white blobs of light everywhere. after a while the feeling went away but i was left really anxious and paranoid. this wasn't just being blazed, i'd been plenty stoned before.

then for months following i would get that same anxiety/paranoia every time i smoked. not as intense as the first time but still noticeable. i'm normally a pretty anxious person, i freak out and overthink things alot, but when im sober i can control it to a good degree. i think after a while pot started to interfere with that control and it made getting stoned really unpleasant around certain people or in certain situations.

i just recently stopped getting these quasi-anxiety attacks after i realized what they were and how to control my thoughts and talk reason into myself. just gotta calm down and rationalize - which i realize is pretty hard to do when you're stoned.

so.. i don't exactly know what i was getting at, but you don't have any brain damage. it's most likely just anxiety and most likely just all in your head. i won't assume to know anything about you but you may just be an anxious person normally and the weed intensified it.