Quitting a bad habit leaves an empty slot in your day. Fill it on purpose or the old habit moves right back in.

Habits occupy time, and removing one leaves that time unclaimed along with whatever need it was meeting. An empty slot is not neutral, it is an opening, and the old behavior knows the way back because the cue, the hour and the boredom are all still there. Replacement works better than removal.

Decide what goes in the gap before you need it, not while you are standing in it. Something available, easy to start and roughly the same length. It does not have to be impressive, only present.