You can’t build momentum while constantly giving yourself permission to stop.

Momentum is fragile in a specific way: it depends on the question of stopping being closed. If you leave yourself an exit at every point, you will spend most of your energy on the decision rather than the work, and the decision will go your mood’s way often enough to prevent anything accumulating. Progress needs a stretch where continuing is simply assumed. Otherwise every day starts from zero.

Commit to a fixed period during which quitting is not on the table, short enough to be honest about. Thirty days is plenty to feel the difference. Reassess at the end, deliberately, rather than every morning by default.