Make honorable behavior familiar.

Anything unfamiliar takes effort under pressure, including doing the right thing. If honourable behaviour is something you do occasionally, it will feel like a departure when it counts, and departures are hard to make when you are tired or afraid. Familiarity is what makes it available.

Look for low-stakes chances to do the decent thing this week. Admit a small mistake, give credit you could have kept, say the awkward true thing. You are not being noble. You are practising.