Then basically, don't snark at people. If you want advice on how to change, there's mine. That's a lot of the reason why I've gotten annoyed over the past few weeks. Unless you're going to add something constructive, there's really no reason to post, either.
I agree with TheCrysCat, there is an old saying that goes "If you don't have anything nice to say, say nothing at all" The irony of that statement exists within this thread, however you could consider it constructive criticism for self-improvement as requested.
BettaMiah, from what I have seen, you don't become 'defensive' but rather you seem to get outright offended when someone is trying to help you or add their opinion/input. When you post your opinion/input and meet opposition or someone who doesn't share your view, you become outright rude.
With time comes patience and understanding, some say age, but I know many young people who are more mature than the immature of my age group. As much as you say you don’t want to calm down or relax, a state of calm and pure acceptance allows you to understand people and empathise with them greatly. This way you can assist further, and also share opinions, have constructive discussions (some call it criticism) whilst remaining un-offended and learning – always learn, never ever stop learning!
Our worst enemy is arrogance when we believe we know everything and stop listening. As PewPewPew stated, your apology then reply post to me was contradictive in what you are trying to achieve initially.
I do hope things work out for you though, and I envy you if you truly don't care what others think of you. That is something I wish I had, but as far as I understand it is human nature to seek approval in others.