If you don’t get enough, take it easy. Ask others around you to take it easy. Make sure you build buffer in your day and don’t pretend to get done with what demands continued attention and concentration.
Hopefully, it’s something you can fix with the following good night of sleep.
Build enough muscles so that you can always be in a position to defuse.
Be the first one to take responsibility and to say I am sorry in every argument, no matter if it’s trivial or crucial. Even when you think you are right, make it so you will own the fact the relationship is cracking.