Any tips on not lashing out in anger?

As a child of a parent that has certain abusive tendencies, I have always kept my anger in when she scolds me but claims it as "helpful nagging". However for some reason today she slapped and threw stuff at me while she was angry at me and I completely lost my shit and retaliated when she hit me...Which led to more stuff being thrown at me. But to be honest her screaming in my face and me not being able to fight back for fear of being hit more was more peeving than anything.

I know I may have some fault to play in this, as much as she does. So I'm asking you guys: How do you not lash out in anger at such people? I know explaining is one, but even now, several hours after the incident my heart is still churning with anger while she pretends nothing has happened?