How do I handle the pressure of never being allowed to make a mistake?

You live with a hard truth: a small slip of yours could genuinely hurt someone. That pressure is heavy, and carried the wrong way it becomes fear that eats at you. But you are learning to carry it differently, as care rather than dread. That is exactly the right turn to make. Vigilance held as fear makes you tense, brittle, and strangely more likely to err. Vigilance held as care is different. It is love in the form of attention, the steady focus you give because a real person depends on you getting it right. Same carefulness, but now it comes from purpose instead of panic. That is a far more sustainable way to hold the weight. Make the vigilance a calm habit rather than a constant alarm. Trust your checks, follow your process, and let the care be quiet and steady instead of anxious. You will not become perfect, no one does, but you can become reliable and clear. Holding your attention as an act of care is the healthiest, safest way to carry a job where the stakes are this real.