You ask for some way of completely eradicating irritability. The inclination to irritability is given us to use against sin, and we were never meant to use it against our fellow men. When we do, we act contrary to our true nature.
Remember that a good action is always either preceded or followed by temptations. God permits this so that the virtue, exercised in that particular action, may be confirmed, consolidated, steeled.
You must set about rooting out the very desire to have things pleasant, to get on well, to be contented. You must learn to like sadness, poverty, pain, hardship. You must learn to follow privately the Lord's bidding: not to speak empty words, not to adorn yourself, always to obey authority, not to look at a woman with desire, not to be angry and much else. For all these biddings are given us not in order for us to act as if they did not exist, but for us to follow: otherwise the Lord of mercy would not have burdened us with them. If any man will come after me, let him deny himself, He said (Matthew 16:24), thereby leaving it to each person's own will ... and to each person's endeavor: let him deny himself.
Let him judge of another’s sin who has not on his conscience that which condemns himself. Let him judge who does not himself do what he judges must be punished in another; lest while judging the other he passes sentence upon himself. Let him give judgment on another’s sin who is not led to deliver it by any hate, by dislike, or foolish levity.
Pray that you may be granted the grace to read the Fathers with the right understanding, the grace to live up to the standards they put before you, and the grace clearly to see your own frailty. You will not long be left wanting and waiting. God will give you help.
When we are incapable of scaling the peaks of virtue, all we have to do is to descend into the ravine of humility. Our humility is our surest intercessor before the face of the Lord.
Remember always that, once we have decided consciously to strive after righteousness, we cannot escape catastrophes and sorrows, no matter where we are.
According to the teaching of the Fathers, any impression which, touching the heart, fills it with a great irritation, must come from the region of passions. Therefore impulses which spring from the heart should not be followed at once, but only after careful examination and fervent prayer. God preserve us from a blind heart! It is well known that passions do blind the heart and screen the shining sun of the mind that we should all strive to gaze at.
A person standing at an open window hears the sounds from outside; it is impossible not to do so. But he can give the voices his attention or not, as he himself wishes. The praying person is continually beset by a stream of inappropriate thoughts, feelings and mental impressions. To stop this tiresome stream is as impracticable as to stop the air from circulating in an open room. But one can notice them or not. This, say the saints, one learns only through practice.
Most people desire and seek after prosperity in this life, and they strive to avoid sorrows. While that seems very good and pleasant, constant prosperity and good fortune do a person harm. He falls into a variety of passions and sins, and angers the Lord, while those who live a life of sorrow come closer to the Lord and more readily attain unto salvation, for the Lord called the life of happiness the broad path. The wide gates and the broad way lead to destruction, and many there be who take that way (Matthew 7:13). It is the narrow way and the strait gate which lead to life eternal, and few there be who find it (Matthew 7:14). Thus, according to His love for us, seeing the possible benefit [of sorrows] to those who are worthy, the Lord moves many off the broad road and puts them on the narrow, sorrowful path, so that in [their] patient endurance of sickness and sorrow, He might effect their salvation and grant them life eternal.
The weather shifts from cloudy to clear and then back to rain; thus it is with human nature. One must always expect clouds to hide the sun sometimes. Even the saints have had their dark hours, days and weeks. They say then that 'God has left them' in order that they may know truly how utterly wretched they are of themselves, without His support. These times of darkness, when all seems meaningless, ridiculous and vain, when one is beset by doubt and temptations, are inevitable. But even these times can be harvested for good. The dark days can best be conquered by following the example of St. Mary of Egypt. For forty-eight years she dwelt in the desert beyond Jordan, and when temptations befell her and memories of her former sinful life in Alexandria beckoned her to leave her voluntary sojourn in the desert, she lay on the ground, cried to God for help and did not get up until her heart was humbled. The first years were hard; she sometimes had to lie this way for many days; but after seventeen years came the time of rest. On such days stay quiet. Do not be persuaded to go out into social life or entertainment. Do not pity yourself, seek comfort in nothing but your cry to the Lord: 'Haste thee, O God, to deliver me! Makes haste to help me, O Lord (Psalm 70:1)! I am so fast in prison that I cannot get forth (Psalm 88:8),' and other such appeals. You cannot expect real help from any other source. For the sake of chance relief do not throw away all your winnings. Pull the covers over your head; now your patience and steadfastness are being tried. If you endure the trial, thank God who gave you the strength. If you do not, rise up promptly, pray for mercy and think: I got what I deserved! For the fall itself was your punishment. You had relied too much on yourself, and now you see what it led to. You have had an experience; do not forget to give thanks.
A prayer offered while one has any cause to reproach a fellow man is an impure prayer. There is only one whom the praying person may and must reproach, and that is himself. Without self-reproach, your prayer is as worthless as it is while you are reproaching someone else in your heart. Perhaps you ask: How can one learn this? The answer is: One learns it through prayer.
God's Scripture gives proof in numerous passages that man must undergo many disturbances in this life; and also that many consolations are at hand. With these, a spirit of sufficient vigor and awareness of the right should overcome present discomforts and look to those things that promise everlasting joy.
One should not ponder divine matters on a full stomach, say the ascetics. For the well-fed, even the most superficial secrets of the Trinity lie hidden.