A card machine takes half a second to think about it, and for a great many people that half-second lands in the stomach.
Money worry lives in the body more than in the accounts. It shows up as a flinch before opening an app, or a call from an unknown number left to ring out.
None of that is a character flaw. It's a nervous system that learned something once and kept the lesson long after the lesson stopped applying.
Releasing it is less an act of will than a slow re-teaching — enough uneventful card readers, enough opened envelopes, until the stomach stops arriving first.