Very often those that are most ready to be angry with others, and to carry their resentments highest for their faults, are equally or still more guilty of the same faults.
In the arena
The anger you direct at someone else's sin is often a mirror. The fault you see most clearly in others is the one you've learned to excuse in yourself.
Pick one person who frustrates you right now, someone whose behavior you keep rehearsing in your head. Before you say another word about them or think another resentful thought, ask yourself honestly: where do I do the same thing? Maybe not in the same way, but in kind. Confess it. Your sin, not theirs. Go to them personally and apologize for your attitude.
James 4:11-12 is blunt: when you judge your brother, you judge the law, and therefore the one who gave the law. A frightening place to be.