Thank past you for studying on that Sunday. Then do something today that future you will thank you for.

You are not one person making one decision. You are a long series of people handing things to each other, and the one studying on a Sunday afternoon is doing a favor for somebody who shows up on Monday in a far better mood. That is the only reliable reason to do hard things early, and it works better than discipline talk because it is just obviously true.

Do one thing tonight that the Thursday version of you will be glad about. Lay out the kit, start the first paragraph, set the alarm properly.