Scared of my anger

I was reading a story here, and when the main character remembered being raped, I was a little surprised at my reaction.

I got mad.

I mean really, really mad. Cold fury ready to hurt something, someone.

For just a moment, I was something dangerous before I managed to get it back under control.

I need a place to get rid of this anger safely, because I'm just a little scared of myself at the moment.