
Rufinus the Presbyter. "Living of Desert Fathers."
(translated from Russian)
We cannot pass over in silence the inhabitants of the desert adjoining the Porfenian sea and bordering the area of the city Diolk. There we saw one wonderful priest, named Piammon, who was notable for the absolute humility and meek indulgence. He was given the grace of revelation. Once bringing the Bloodless Sacrifice to the Lord, he saw an Angel of the Lord near the Altar: he was holding a book in which he wrote down the names of the monks who approached to the Holy Altar. The elder carefully noticed whose names the Angel missed. After the end of the liturgy, he summoned separately each one of the missed by the Angel and asked him whether he had some secretly committed sin in the conscience. At this confession, he revealed that each of them was guilty of a mortal sin ... Then he persuaded them to bring repentance, and casting himself down before the Lord along with them, prayed with tears day and night, as if he was involved in their sins. And he was in repentance and tears until he saw the Angel again, standing before the Altar and writing down the names of those who were taking the Holy Mysteries. Having written down the names of everyone, the Angel even started to call each one by name, inviting to come to the Altar for reconciliation with God. And the elder, seeing this, understood that their repentance was accepted and happily admitted everyone to the Altar.
http://agapienxristou.blogspot.ca/2013/09/angel-did-not-write-down-names-of-those.html

The Letters of Saint Ambrose of Optina.
I have received your letter dated 30 September. You write about yourself in this way: "For more than two years I have been ill with an unknown illness which doctors can not understand. The disease is such that I have more fear, especially reciting the Divine Liturgy, and also the constant melancholy, and pensiveness, and anguish. Though it is inconvenient to resolve this kind of confusion and disease without seeing you, but considering melancholy and fear you experience, I think that the beginning and the first cause of your disease were your childhood sins that probably you could not confess properly or were ashamed to do it; but you should had done it especially before your deacon ordination. The second cause may be that you haven’t always kept your conscience clear combining deacon ministry with married life, because a person ordained into this service is required a particular keeping of conscience, which is not infrequently prevented by either excessive use of strong drinks or intemperance with respect to irritation and anger. Each of these weaknesses alone has the power to bring great harm to the soul, especially if they are combined at the same time.
The same condition and state happens when a man despite his weaknesses and failures does not humble himself, but becomes arrogant and abases others. I think that in your sickness, first of all, you need to strive for release from aggravating anguish and fear. And you can achieve this, first, if you can find in your region such a confessor to whom with full faith and perfect sincerity you could humbly confess everything that lied heavy on your conscience from six years to this day; and secondly - if you firmly decide not to return to such actions that cause fear and anguish, as the Lord Himself said in the Gospel to the sinner, “go, and sin no more” (Jn 8: 11). If you do so and from now on you are determined to keep yourself and your conscience, then we can hope that you will not only get rid of the grief and fear aggravating you, but you can get such a relief in your bodily disease, with God’s grace and help, that will be useful for you, by the will of Lord, All-good, All-knowing, Almighty and having the providence of salvation for everyone.
Saint Ambrose of Optina
http://agapienxristou.blogspot.ca/2012/11/fear-during-divine-service-because-of.html