I understand, and it's difficult to deal with criticism when it's both rude and correct. However, it's important to consider how something is said is just as important as what is said. Take my OP for instance: I still think they're correct, at least partially, but how they wrote the first half was perhaps too brash. (I don't know if that's how diminoten intended the statement to be interpreted.)

The reason I say this is because, quite frankly, if you hadn't taken what was said personally, internalizing it as thus, you would still be writing and none of this conversation would have taken place. You disagree, and I understand; however, recognize that as an outsider looking in, I think you're too dismissive of the impact this interaction had on your work (you stopped writing). It doesn't matter whether the person was right or wrong: The fact they said they didn't trust you because of a single mistake was demeaning.

For what it's worth, I still stand by what I said earlier: If someone isn't willing to write constructive criticism, preferring to resort to negative language or insults, then nothing they say matters. If they're right, they're right, but the best you can do is just ignore the negative sentiments and move on. It's not easy. You'll second guess yourself (as you're doing). And you know what? That's fine! You'll be more cautious next time, and you'll have the added confidence that you can deal with similar responses in the future (I'm serious).

To put it another way: It's not so much that the individual in question was correct that dinged your confidence--it's how they said it. I'm almost certain had it been written differently you'd have thought nothing more of it; e.g. "Hey, I think you meant to write 'certified' rather than 'certificated.' Just thought I'd let you know."

Think for a moment on that. If this were written instead, would you still feel your confidence had taken a hit? I'd wager not!

Chin up, my friend. If an asshole is right about something, it doesn't make them less of an asshole--they're just an asshole who happens to be right.