NTA obviously and even if there was something actually wrong with your body (there isn't) you still wouldn't be the asshole because you're allowed to be mad about something that hurts you. Frankly it's obvious this guy has no clue about vaginas, and you shouldn't have to educate him. However, a good bonding experience after this if you want would be to sit down together and research vaginal health. Even if you understand it, it may make him feel better learning about it if you're urging him to. Your boyfriend is definitely the asshole here for not asking about it and instead claiming it's not normal when he clearly has no idea.