Intense emotions come from a part of your brain that has the power to highjack you and take over. When you feel some force is taking over and you are about to blow up, tell yourself to "STOP".
That part of your brain cares about no one and has no problem hurting people. Before lashing out, take a time out. Remove yourself from the upsetting situation. Remind yourself that the person you are about to attack is human just like you.
Take the time to write down your concerns and to find a constructive solution before going back to the conversation.