Even if you usually do vegetables properly, keep some bags of frozen precut veg around for when you are tired. You can often drop it in the pan of whatever meat you're cooking, or into a stew or soup. Keeps you having veg even when you are behind.
Macro hacks: Oats, oats, oats. Carbs and protein in a pinch. Flavour them however or don't. I don't.
Final word: fitness and health are the same thing. You can't be truly healthy and vital with diet alone. The mind needs movement, your body needs it. You don't need to be a bodybuilder, just get moving whichever way is fun for you. I do strength training and cycling.