Is it ever OK to be angry?
Someone who is angry only because they have been wronged or think they have been wronged is not righteously angry, that is a sinful anger.
"And Jesus entered the temple and drove out all who sold and bought in the temple, and he overturned the tables of the money-changers and the seats of those who sold pigeons. He said to them, it is written, 'My house shall be called a house of prayer,' but you make it a den of robbers." - Matthew 21:12-13
Here, Jesus is angry that God's house has been defiled, he is angry because God has been wronged, not because his comfort has been disturbed or he has been inconvenienced but because the God of the universe has been greatly sinned against.