Along with the above advise stated above, you might also want to consider looking at what your diet is like. Your anger and frustration might actually be because you're lacking something.
I'm no nutritionist, but I know that what you put in your body will effect your mental performance very heavily. For instance, lack of B vitamins can make you very depressed and give you hopeless thoughts (I know this from experience), and make you fearful. Also, lack of sleep and not eating enough can make you irritated and uncharitable.
You might want to research that and see what kind of foods you should be eating/what kind of foods you are eating now, so you can assess why you may become more angry or more frustrated over things that may not be as bad as you are making them to be.