There are jerks on the internet planet. Deal with it.
I can sugar coat my post with "daww I hope it never happens again", but it the reality is that it will happen again, be it ingame or elsewhere.

You will find plenty of neutral/positive players too. If you don't stress too much about bad experiences, it will be better for your blood pressure.

However, don't ignore all criticism either. Sometimes there is something to be learned from criticism, even if was delivered poorly.
e.g. If someone says "stupid noob! get gld to 22 for provoke before doing raids!", don't ignore that advice. Take the advice and never be called out on it again.