01
The idea
Everything above works while you are calm and is unavailable while you are not. The solution the tradition arrived at is external: write it down, carry it, and read it rather than trying to reconstruct it under load.
This is what the Handbook itself is. Arrian compressed Epictetus's teaching into something small enough to be held — the Greek encheiridion means something you keep in your hand, and the word was also used for a dagger. Both meanings are apt.
Your version is one card: the fear, the two claims, the three actions, and the one sentence you will say to yourself when it arrives. It is not impressive. It is available, which is the only property that matters at the time.
02
Why this matters
Under pressure you do not rise to your understanding; you fall to what is written down. Every field that operates under real load — aviation, medicine, the military — reached this conclusion independently and built checklists.
A card also removes the negotiation. When the moment arrives, the decision has already been made by a calmer person with better information, and your job narrows to execution.
And it makes the practice honest. A fear you cannot write in one line, with three actions under it, is a fear you have not yet examined — the writing exposes that immediately.