Play a clone of Tetris
Tetris has suggested efficacy in attenuating development or severity of trauma and it seems to have a beneficial ongoing cognitive effect also.
Don’t get Tetris™️, get a good paid version that lets you buy it and doesn’t show ads or track you after buying.
Not off hand but here’s the fdroid page: https://f-droid.org/en/packages/com.zhenxiang.superimage/