Pray simply. Do not expect to find in your heart any remarkable gift of prayer. Consider yourself unworthy of it. Then you will find peace. Use the empty cold dryness of your prayer as food for your humility. Repeat constantly: I am not worthy; Lord, I am not worthy! But say it calmly; without agitation.
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.
Not one of us can boast of having acquired humility: our actions, the whole of our life, prove the contrary. And where there is a lack of humility, pride is always present. Where light is wanting, darkness reigns.
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 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.
The Holy Fathers recommend 'moderate' fasting; one ought not to allow the body to be weakened too much, for then the soul, too, is harmed. Nor ought one to undertake fasting too suddenly; everything demands practice, and each one should look to his own nature and occupation. To choose among different kinds of food is to be condemned; all food is God-given, but it is advisable to avoid such kinds as add to the body's weight and appetite; strong spices, meat, spirituous drinks and such foods as are solely for the palate's enjoyment. For the rest, one may eat what is cheap and most easily available, they say. But by 'moderate' they mean one meal a day, and that one light enough not to fill the stomach to satiety.
It took Noah a hundred years to build his ark; log upon log he dragged to the construction. Do as he did; drag log upon log to your construction, patiently, in silence, day after day, and do not inquire about your surroundings. Remember that Noah was the only on in the whole world who 'walked with God' (Gen. 6:9), that is, in prayer. Imagine the crowding, the darkness, the stench, that he had to live in until he could step out into the pure air and build an altar to the Lord. The air and the altar you will find within you, explains St. John Chrysostom, but only after you have willingly gone through the same narrow gate as Noah.
In his famous book, 'The Ladder', St John Climacus records the life of this saint. The young Acacius was a novice with an evil elder in the monastery on Sinai. The foul-tempered elder daily groused and grumbled at Acacius, and often beat him, tormenting and ill-treating him in every possible way. Acacius did not complain, but bore it all patiently and with trust that it would work for his salvation. When anyone asked him how he survived, he replied : 'Well, as before the Lord God'. After nine years of obedience and ill-treatment, Acacius died. The elder buried him and then went off to lament to another elder, a holy man, saying: 'Acacius, my disciple, is dead. 'I don't believe it' replied the holy elder , 'Acacius is not dead.' They then both went to the dead man's grave, and the holy elder called out: 'Brother Acacius, are you dead?' The obedient Acacius, obedient even in death, replied: 'I am not dead; the obedient cannot die.' Then the evil elder repented and shut himself in a cell near Acacius's grave, where he spent the rest of his life in repentance and prayer.
Remember always that, once we have decided consciously to strive after righteousness, we cannot escape catastrophes and sorrows, no matter where we are.
But, say the saints, now that you recognize the darkness in your own heart and the weakness of your flesh, you lose all desire to pass judgment on your neighbor. Out of your own darkness you see the heavenly light that shines in all created things reflected the clearer: you cannot detect the sins of others while your own are so great. For it is in your eager striving for perfection that you first perceive your own imperfection. And only when you have seen your imperfection, can you be perfected. Thus perfection proceeds out of weakness.
You are, I am sure, aware that for you penitence is now no longer limited to disclosing your sins to your confessor, but that you must now bear your sins in mind always, until your heart nearly breaks with their ugly load; and would break, were it not for your firm faith in the mercy of our Lord.