What are some tips you can give me to figure out exactly why I am so angry?
In my book, The Forgiving Life (2012), I have an exercise that I call The Forgiveness Landscape. In this exercise, you start in your childhood and try to recall the central unjust incidents and the people who were unjust to you. You then rate your level of anger on a 1-to-10 scale. You do the same for your adolescence, and the same for your adult years. You then order the people/incidences from the lowest (but still significant in your life) to the highest levels of anger. This will give you a profile of your anger. I then recommend that you start with the lowest level of anger and forgive that person. Move up the anger-ladder until you have forgiven the person toward whom you have the most anger. This should aid you in not only gaining insight into your anger, but also at whom you are angry, and then to rid yourself of that anger.
For additional information, see The Four Phases of Forgiveness.