Lord Jesus Christ, Son of God, Have mercy on me, A sinner.
For about the last decade the Jesus Prayer has been a spiritual lifeline.
That is a pretty exact analogy - when I am stunned, confused, feel myself slipping, it is what I repeat to myself in a kind of desperation.
And like a lifeline - once I have been saved from the immediate threat of drowning, I would move on to other things; other prayers or meditations.
So I don't go along with the Eastern Orthodox ideal of aiming to say the Jesus Prayer 24/7. I think that would be like living one's life doing not much but gripping onto a lifeline; and I am sure that God wants more than that from most of us.
But a lifeline is a precious thing to have access to; and the Jesus Prayer can helpfully become almost an automatic response to the sense of being 'swept away' by the tide of evil*.
*That's why the "a sinner" at the end is valuable. It is at those moments of incipient and beginning (as well as done) sin when the prayer has most value for me; including for such mainstream modern sins as fear, resentment and despair.
H/T Adam Piggott for triggering this comment through his post.