Clock - like Candu says, you are already doing some good things to deal with the anger. i think another needed component is - being heard, understood and validated. it is important to not just send our ranting and expressions of hurt - because that is what usually causes the anger - feeling violated or disrespected in some way - into a void. there needs to be a human ear and brain and emotional connection there to receive what we are sending in order for us to feel better. that is what you are doing here.
i hear you, man!
i agree with you!
the situation sucks!
and you have the right to feel abused by it! (that for me is the biggest trigger - when someone makes me angry it is subconsciously reminding me that i am/was a victim.)
hope this helps. is there anyone near you that you can vent to? that might be helpful. someone who will listen and tell you that your feelings are justified.
"That you are here - that life exists, and identity; that the powerful play goes on and you may contribute a verse. . . What will your verse be?" Robin Williams as John Keating in "Dead Poets Society"