Motivation called in sick. Routine still showed up for work.

Feeling like it is an unreliable employee. It arrives on the easy days and disappears exactly when the work matters, which is why building anything on top of it keeps collapsing. A routine does not consult your mood. It runs on a time and a place, and that is precisely why it survives the weeks when you have nothing.

Choose the time and the location before you need them, so the decision is already made. Same desk, same hour, minimum amount. On the flat days, do the smallest version rather than nothing, because the habit is what you are protecting.