It is as necessary for a man to say the Jesus Prayer as it is for a ship in danger to send out steadily the S.O.S. signal: Lord Jesus Christ have mercy on me.
Confess your sins not to the priest, but to the Lord Himself, only without hiding anything, from your whole heart. The priest is the mediator between you and God, and so the benefit of Confession depends on your open-heartedness.
The late Athonite Father Tikhon used to say: The prayer, 'Lord Jesus have mercy on us' is worth one hundred drachmas, but 'Glory to God' is word one thousand. Glorifying God is more valuable than anything else, because in the first instance, people often say the Jesus Prayer when needing something; but when one glorifies God in the midst of suffering, it is an ascesis.
We should not miss any chance to us to say the Jesus Prayer. We must not let our mind wander in vain things. In saying the Jesus Prayer one's mind finds rest and joy. It is like small children who for the whole day run around, shouting and playing and hitting each other. But the one thing that gives them rest and great joy is when at night they find themselves in their mother's arms. This way also one's mind instead of being scattered about, out to be devoted to mental prayer.
In words of boastfulness and self-justification there always lie concealed contrariness and pride, from which God turns away. After sinning one ought immediately to 'flee.' But you say, where? To the calm haven of heartfelt repentance.
One time St. Nicodemos, on a feast day, was walking toward the Great Lavra (on Mt Athos). On his way he came across a kellion where he spent the night. At midnight he saw an elder and his accompanying monks entering the church. He secretly went in also, and there he saw the elder and his subordinate monks uttering the Jesus Prayer ('Lord Jesus Christ, Son of God, have mercy on me'), sometimes in a kneeling position, sometimes standing up. And at the time of the Holy Communion, he saw all their faces shining only a little less dimly than the sun.
She was begotten like the cherubim, from pure and spotless [clay]. For while she was still in the loins of her father Joachim, her mother Anna received a message from a holy angel, who said to her, 'Thy seed shall be spoken of throughout all the world.' Therefore Anna brought her to the temple of the Lord as an offering. And during all her time there, the maiden stood alongside Christ the King, 'at his right hand, splendidly robed in a robe of gold,' as the prophet says 'Listen, daughter, and see, and incline thine ear; forget thy people and thy father's house. The King greatly desireth thy beauty; he is thy Lord -- pay homage to Him' (Ps. 44:10-13).
I must tell you that annoying incidents are unavoidable in this life. Those who are experienced in the spiritual life say that such incidents can even bring profit to the soul. Through annoying incidents we come to recognize that we are impatient - and if we are impatient, that means we are proud. And this awareness should dispose us to self-reproach and repentance, and to asking mercy from the Lord in prayer. But without annoying incidents a man is inclined to conceit.
What guarantees a safe journey to eternity is effort, dignity, the sense of being unworthy before God, hope (the spiritual oxygen), consolation, and certainty. Not misery and compelled obedience and forced prayer; not tears and sadness - these all come from Satan. Yes, I ought to weep for my sins, but all the while hoping in God's love. But I cannot stand it if I cry because the devil wants me (to despair). Many times Satan crushes a person with despair and the devil becomes the victor. But this does not happen when one is like a child on his father's arm - trusting. Our trust in God is a ceaseless prayer that brings positive results. Despair comes from the devil. Don't say, 'Oh, what has happened to me?' but give yourself to God totally and hope in Him.
You write that after Communion you felt well. Glory be to God, Who comforts our unworthiness. And as regards the fact that this soon passed, here also is seen His fatherly providence for us. For continual consolation enfeebles the soul and makes it slothful, or leads to even greater harm. That is why the Lord takes it away quickly and again makes us feel our weakness, our helplessness, and our sinfulness. We must humble ourselves more, reproach ourselves, offer repentance for our sins, and not desire consolations, but patiently endure what God allows. Dryness and cooling of fervor are also permitted on account of vainglory.