If you're stuck, make the next step ridiculously small. Open the file. That's it. Now write one sentence. Now another. You are moving and motion creates momentum in a way that thinking never will, so keep the bar low enough to step over and high enough to matter.
You owe no one your attention until you have paid yourself 30 minutes of deep work. Try that for a week and watch what changes in how you feel about your own promises to yourself and the way you keep them when no one else is watching.
Small daily improvements are invisible at first, then transformative. This is how 1% compounds into something you no longer recognize — quietly, then all at once — if you just keep showing up when it's easy to quit and the room is empty and nobody is clapping yet.