I go pretty much straight from work to yoga, make supper at a civilized hour afterwards, and take Wednesdays off workouts to, as you say, flop.

Gardening I do in the morning before work.

Cooking I do because others depend on me, that’s been true for 30 years now, before that I didn’t remember to eat, just when hungry. Don’t keep junk in the house if it tempts you, make your easy stuff healthier. Hummus, boil eggs on the weekends so you have those, fruit, bagged salad greens, make it easier to eat nutritious food.

I want to say suck it up and go to the gym, you will be glad you did. 9-5 is pretty nice hours, here it’s 8-5 or 9-6. Exercise is one non-negotiable for me. I have gotten up at 5 to run when that was the only option, and have gone to the gym at 20:30 after night classes after work when that was the only option. You will feel better if you just GO and work out even if you don’t want to.

Habit>willpower. Commit to 6 weeks, and by then your schedule will probably settle out. Personally I put exercise ahead of healthy eating because I know my body.