You do not need to be that hard to yourself when your feeling “wrong”. Yes it is probably better for yourself if you don’t overreact. However you cannot really cotntrol your feelings. So it is still better to accept your anger. First, as you said, it drives up the frustration, because now you are also worried about your feelings. And second your original emotion wants to be “noticed”. I read and experienced a few times myself, the “wrong” emotion disappears often quickly when you accept it. It is an essential concept of mindfulness, to accept your emotions.
Edit: As far as i understand it and experienced it, saying to yourself “no i shouldn’t be angry about this” won’t change your thinking