They indeed say patience is a virtue. Over the course of your personal history four factors have worked together to shape your current behaviors, habits, and practices.
A shift in any one of the four, thoughts, feelings, words, and actions, will cause the others to shift. Some of your instinctive impatient reactions are simply the conditioning you have trained yourself in to handle stress in one or all four areas. The way to overcome impatience is work on shifting one of the four. Watch what happens.