Breaking promises to yourself teaches you to stop listening to you.

Every private commitment you abandon adjusts the internal odds slightly, until your own plans stop registering as real information. That is why intention eventually stops producing action, and it is also why the repair is not a more ambitious plan. Trust in yourself gets built the same way as trust in anyone else, through a run of small kept agreements nobody else sees.

Make one commitment this week so small that failing is nearly impossible, then keep it exactly. Repeat it next week. What you are rebuilding is less discipline than the belief that what you say to yourself counts.