Why not make up your own? You're a writer, right? :)
Below is a link to the Catholic commendation of a departing soul:
https://www.catholicculture.org/culture/liturgicalyear/prayers/view.cfm?id=1134
The priest says it over the person who is about to die. If one is about to ctb, I suppose one can adapt it like this:
Go forth, O Christian soul, from this world, in the name of God the Father Almighty, who created me; in the name of Jesus Christ, Son of the living God, who suffered for me; in the name of the Holy Spirit, who was poured forth upon me; in the name of the glorious and ever blessed Virgin Mary, Mother of God; in the name of St. Joseph, chaste Spouse of the same Virgin; in the name of the Angels and Archangels; in the name of the Thrones and Dominations; in the name of the Principalities and Powers; in the name of the heavenly Forces, Cherubim and Seraphim; in the name of the Patriarchs and Prophets; in the name of the holy Apostles and Evangelists; in the name of the holy Martyrs and Confessors; in the name of the holy Monks and Hermits; in the name of the holy Virgins and of all the Saints of God: may my place be this day in peace, and mine abode in holy Sion. Through Christ our Lord. Amen.
O merciful and gracious God, O God, according to the multitude of Thy mercies Thou blotteth out the sins of such as repent, and graciously remit the guilt of their past offenses, mercifully regard me, Thy servant (handmaid), and grant me a full discharge from all my sins, who with a contrite heart most earnestly begs it of Thee. Renew, O merciful Father, whatever has been vitiated in me by human frailty, or by the frauds and deceits of the enemy: and associate me as a member of redemption to the unity of the body of the Church. Have compassion, Lord, on my sighs, have compassion on my tears; and admit me, who has no hope but in Thy mercy, to the sacrament of Thy reconciliation. Through Christ our Lord. Amen.
Me again. The prayers are rather long: these are just the first two of them. I think they are prettier than just about anything I could make up. For example, here is the scene in my alternate history where Asquith is about to ctb:
Asquith picked up the revolver. It felt heavy. His breathing was jagged and his heart was beating quickly, as if to protest against his decision. He whispered the Lord's Prayer. "Forgive me, God, for all this trouble," he then murmured. There! The muzzle was above his heart. Here it goes, he thought —
And pulled the trigger.
Of course, Asquith was not a Catholic: he had been raised a Congregationalist, and as an adult at least nominally adhered to a Broad Church Anglicanism. He would have probably found "Go forth, O Christian soul" rather long-winded and convoluted.
