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.
Watch constantly, learning to understand God's law, for this warms the heart with heavenly fire. Guard your lips from the idle word, or empty talk, lest the heart gets used to evil words.
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.
In the eyes of God, it is always preeminently right that a man should spend himself in devising new means for spreading consolation to his subordinates, who are his charges.
When you intend to do something and see that your thought is perturbed, and if after invoking God's Name it remains perturbed even by a hair's breadth, know from this that the action you mean to commit is from the evil one and refrain from commiting it. For nothing done with perturbation is pleasing to God.
Faith is truly a gift, gained for us through Christ's advent. But this does not abolish our freedom or responsibility. God desires of us not only faith but action too.
Do not judge and do not belittle anyone, because from this the heart grows faint and the mind is blinded, and from this, negligence appears and unfeelingness of heart is born. Keep ceaseless vigil, learning in the law of God, for through this the heart is warmed by heavenly fire, as is said: 'In my meditation a fire was kindled.'
If Nabuzardan, the court cook of the King of the Babylonians, had not gone to Jerusalem, then the Temple would not have burned (cf. 2 Kings 24), That is to say, a person’s mind is not attacked by the flames of carnal pleasures, if a person is not conquered by gluttony.
In answer to your question as to what constitutes a happy life, whether splendor, fame and wealth, or a quiet, peaceful, family life, I will say that I agree with the latter, but will add the following: A life lived in humility and with an irreproachable conscience brings peace, tranquility, and true happiness. But wealth, honor, glory and exalted position often serve as the cause of a multitude of sins, and such happiness is not one on which to rely.
Do not think that even here any one of us constantly enjoys consolation. No: here, as everywhere, flesh and mind are at war; here as everywhere, there is falling into pride and purification through humbling: here, as everywhere, we long for consolations but must learn to carry a weighty cross. This cross tests our love. Can we, do we love God even under the weight of the most bitter adversities?
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.