Lord Jesus Christ, Son of God, have mercy on me, a sinner.
This one is not in the service books, and the page would be dishonest to imply otherwise. It belongs to the ascetic tradition — the desert fathers, the Philokalia, the prayer rope — rather than to the offices. The English is settled and has been for centuries.
Where these come from. Every prayer here is transcribed from a printed book that is out of copyright, and each one says which book and where in it. That is not fussiness. An English translation of an Orthodox prayer is a copyrighted work in its own right, separately from the Greek or Slavonic behind it, and in 2012 a monastery took a bishop to federal court for putting its translations on a website — and won. So these come from Hapgood's Service Book of 1906 and Shann's Euchology of 1891 and Book of Needs of 1894, which anyone may reprint. More on the sources and what is missing.