As long as you direct the anger where it's appropriate then go ahead. But lashing out at people who are trying to support you is not the appropriate channel - even if you are angry at them. Especially on a forum such as this, where you can safely assume that by default everyone on this site is dealing with some sort of mental health issue. Yelling at them or invalidating them when they are trying to be helpful may just trigger them too and make them feel worse. Their feelings and experiences need to be considered just as everyone else tries to consider yours.

There have been many times where the things that I've wanted to say, to both you and other users, would come off as way too harsh and upsetting. So I either spend the time to reword things so that it will be a bit easier to digest, or I refrain from posting. I don't respond in the heat of the moment precisely because I am aware of the fact that other people have issues of their own to deal with.

And I think one reason why lashing out in anger is not appropriate is because anger often leads to abusive behaviours - many of us on this site have been abused in multiple ways, so why contribute to that cycle? Feeling angry is totally fine. No one can help how they feel. But you can choose how to act.