My condolences to you and your family. Prayers said for the repose of the soul of your cousin David.
May the Church’s prayer below bring you and your family as much comfort as it does to me when I pray it for a loved one. The leader’s part is in blue, responses (are written once and repeated) in fuchsia.
The Litany for the Faithful Departed

Lord, have mercy on us.
Christ, have mercy on us.
Lord, have mercy on us. Christ, hear us.
Christ, graciously hear us.
God, the Father of Heaven,
have mercy on the soul of David.
God the Son, Redeemer of the world, . . .
God the Holy Ghost, . . .
Holy Trinity, One God, . . .
Holy Mary, Mother of God,
pray for the soul of David
St. Michael, . . .
All ye angels and archangels, . . .
All ye orders of blessed spirits, . . .
St. Joseph, . . .
All ye holy patriarchs and prophets, . . .
All ye holy apostles and evangelists, . . . .
All ye holy martyrs, . . .
All ye holy bishops and confessors, . . .
All ye holy doctors, . . .
All ye holy priests and Levites, . . .
All ye holy monks and hermits, . . .
All ye holy virgins and widows, . . .
All ye saints of God, . . .
Be merciful.
Spare him, O Lord.
Be merciful.
Graciously hear us, O Lord.
From all evil,
O Lord, deliver him.
From the rigor of Thy justice, . . .
From the power of the devil,. . .
From long-enduring sorrow, . . .
From cruel flames, . . .
From horrible darkness, . . . .
From dreadful weeping and wailing, . . . .
Through Thy holy nativity, . . . .
Through Thy most sweet name, . . . .
Through Thy most profound humiliations, . . . .
Through Thy bloody sweat, . . . .
Through Thy scourging, . . . .
Through Thy crowning with thorns, . . . .
Through Thy carrying of the cross, . . . .
Through Thy most cruel death, . . . .
Through Thy five most holy wounds, . . . .
In the Day of Judgment,
we sinners beseech Thee, hear us.
Thou Who forgavest Magdalene, and didst grant the prayer of the thief,
we beseech Thee, hear us.
That Thou wouldst be pleased to deliver the souls of our parents, relations, friends, and benefactors, from the pains of hell,
we beseech Thee, hear us.
That Thou wouldst be pleased to have mercy on those of whom no special remembrance is made on earth, . . . .
That Thou wouldst be pleased to grant them all the pardon and remission of their sins, . . . .
That Thou wouldst be pleased to receive them into the company of the blessed, . . . .
King of awesome majesty, . . . .
Son of God, . . . .
Lamb of God, Who takest away the sins of the world,
grant unto him eternal rest.
Lamb of God, Who takest away the sins of the world,
grant unto him eternal rest.
Lamb of God, Who takest away the sins of the world,
grant unto him rest everlasting.
Christ, hear us.
Christ, graciously hear us.
Lord, have mercy.
Christ, have mercy on us.
Lord, have mercy.
From the gate of hell,
deliver his soul, O Lord.
O Lord, hear my prayer.
And let my cry come unto Thee.
Let us pray.
O God,
the Creator and Redeemer of all the faithful,
grant unto the soul of Thy servant departed the remission of all his sins;
that, by pious supplications,
he may obtain the pardon which he has always desired.
Grant this, O God, Who livest and reignest for ever and ever. Amen.
O eternal God,
Who, besides the general precept of charity,
hast commanded a particular respect for parents, kindred, and benefactors;
grant, we beseech Thee, that, as he was the instruments by which Thy providence bestowed on us our birth, education and innumerable other blessings, so our prayers may be the means to obtain for him a speedy release from his excessive sufferings, and admittance to Thine infinite joys. Through Jesus Christ, Our Lord.
Eternal rest give unto him, O Lord.
And let the perpetual light shine upon him.
May he rest in peace.
Amen.

**
Let Nothing Disturb You
Let nothing disturb you,
Let nothing frighten you,
All things are passing away:
God never changes.
Patience,
Obtains all things,
Whoever has God
Lacks nothing:
God alone suffices.
Santa Teresa de Jesús
(Santa Teresa de Ávila)**
Luz María