The bridge behind you only becomes a problem when you keep walking backward to check it.

An ending only stays a problem while you keep returning to inspect it. Each look back re-establishes the connection, re-opens the question, and stops the forward movement that would otherwise make it irrelevant. The bridge does not need checking. Your attention is what keeps it in the picture.

Notice how often you revisit something already decided. Set a limit on it if you need to, an amount of time per week. Then spend the rest of your attention on where you are actually walking.