<human>: Can you condense the text into three sentences or less?

My gf and I have been dating for almost 2 years now and we've got into some serious arguments recently where weve almost broken up. She can get angry pretty easily and im typically a calm person.
 
Basically what happens is that my gf will get mad at something for whatever reason and then she takes out the anger on me (nonviolent). 75% of the time im able to bring her back to normal as im a real calm person but sometimes when im already not in he greatest mood I get angered as well. This will then lead to her getting extremeely mad at me because she feels that when shes mad I should just calm her down and not get mad at her. 
Ive tried explaining to her that yes thats true but also if you say shit that will get me mad you cant expect me to just take it and try and comfort you. But she stands by her thought that when one person in the relationship is mad the other person just has to comfort them and not get mad at them, basically saying only one person mad at a time. 

I just need some thoughts from otber people on this please its really starting to ruin our relationship. Other then when she gets mad, she is the most sweetest, lovongcaring person you will ever meet but this one thing just ticks me off.

Note: ive only ever seriously got mad at her once in this whole relationship over some stupid comments she said and then guess what,she did exactly what she hates, and gets mad at me. She apologized and said next time ill just comfort you likr isaid I would. This happened about 6 months ago and ive never really gotten mad at her sice then so its never been tested so to speak

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<bot>: my[24 M] gf [21 F] believes that only one person in the relationship can be mad at a time, the other needs to comfort</b>