Your past and present torments and sufferings are poured down upon you to test your faith and 'steel' it; they also work to curb your lusts and passions. Humble yourself. God gives help to the humble. Judgment of others, insistence on their shortcomings, can only increase the bitterness of your sorrow. Choose the better part.
As soon as a man becomes humble, mercy is not slow to envelop him. Then the heart is aware of God’s help, and acquires a certain power of assurance (in God) which arises in it. And when a man is aware that God’s help is actually assisting him, his heart becomes filled with faith in very truth.
The man who is conscious of his sins is greater than he who profits the whole world by the sight of his countenance. The man who sighs over his soul for but one hour is greater than he who raises the dead by his prayer while dwelling amid many men.
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.
Do not be surprised that when you draw near to virtue, grievous and intense tribulations come to you on all sides: for virtue is not considered virtue, if it does not involve hard work.
Bear this in mind: the Christian life is an unending spiritual fight. The wily enemy cleverly uses snares and arrows without number. Before some of us he spreads the lure of worldliness, the outer pride of pomp and circumstance, the cruder lusts-the lusts of the flesh. But those of us who are not attracted by any of this he leads up on to the peaks of subtler prides. Having got us there-to the high country of self-esteem-he causes a dark mist, the mist of the subtlest prides, to enshroud our intellect. Then he leads us, his blinded slaves, away from God, without our even suspecting it. Mark this too: it is not very hard for the simple sinner to come to hate his foul life and, leaving it, to fling himself on the mercy of God; but it is very hard for the subtler sinner-the self-sufficient one-to let a ray of divine love pierce the leather jacket of his self-righteousness... Humility is the only weapon that wards off all attacks, but it is difficult to fashion, and the art of using it is often misunderstood, particularly by those who lead an active, worldly life.
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 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.