A few tips:
1. The breathing that other people have already suggested is good. But you need to practice multiple times a day even when you are not feeling angry for your body to start using it as a go to response. You won't be able to rationally think during those bouts of anger about how you should be responding. Just won't happen.
2. Your feelings of inferiority are driving your anger, and bottling so many emotions makes it impossible for you to handle minor irritations in an appropriate way. They just top off the bottle and boil over out of the top. I would strongly suggest seeing a counselor to work on your self-esteem, recognition and acknowledgement of your emotions, and tactics for restructuring your thoughts and handling your emotions.
3. Journaling could be good if you do it well. I find though that a lot of people really have no idea how to journal in a way that will provide either insight or release. At work we have the ladies do thinking reports and it looks a lot like this, though the form isn't exactly the same. The elements are all pretty much there though.
Thinking report
They get turned into me which does a couple of things. It increases my insight into what the client is thinking/feeling, and they provide an opportunity for them to get feedback about very specific elements of situations. In addition, they help them to increase their own insight and over time they seem to encourage change, recognition of thinking errors, etc.
4. Examples of thinking errors would be things like "crisis building" which is expecting crisis situations based on limited information and getting yourself worked up about it; or black and white/ all or nothing thinking.
Google thinking errors and you should find lots of resources on those. Recognizing them and correcting for them can go a long ways towards reducing anxiety, anger, etc.