There was a thread about Japan and food together and no one told me?
FrozenBacon, you are completely ridiculous. Remember, Japanese food doesn't consist solely of "gross" seafood dishes. I mean, how gross are noodles? Rice? Beef tongue ice cream?
But seriously, it seems like a lot of weird/gross attitudes come from squid/eel/octopus/raw fish food, as evidenced in this thread. And don't buy food from weird people on the street. Was it possibly roe that you ate?
What have you tried? Perhaps you could try something arguably tamer, like bamboo shoots, hijiki, various preparations and kinds of seaweed/kelp, black beans, taro root, mochi, gyoza, deep-fried tofu, deep-fried chicken...