Why am I so angry?
I have written in the past about the way that intense emotions, disproportionate to the trigger, are worth examining more fully. I wouldn't want to generalise, because everyone is unique, and trauma take different forms, but an overwhelming, swift reaction will often have its roots in your past.
Emotions are a sign that our needs are either being met, as in the case of agreeable feelings such as joy, contentment and so on, or NOT being met, as in the case of unpleasant or destructive emotions such as rage, sadness, jealousy.
Anger is a particularly interesting emotion. Traditionally, it is one that women struggle with, as it is not seen as acceptable in the same way as it is in men.
If you agree with the idea that all emotions are an attempt by our Ego to look after us, then it can be helpful to try and work out what useful purpose anger may serve. Feelings come from a different place than rational thought, so sometimes they are misplaced. Anger might be in response to a genuine threat, and prepare you to act in a way that could literally save your life. However, anger that arises in a way that confuses you, like an emotional hijacking, can have destructive results. It can rupture relationships and leave you with feelings of shame.
If you are able to recognise this in yourself, then you can try to notice what triggers it, and work out if there is a pattern. What need is not being met here? A need for safety? Respect? To be heard? Are your boundaries being trampled?
Once you are able to understand the need that is being unmet, you can perhaps communicate this to the other person, or to look at ways you can meet this need in yourself.