Keep it simple, invest in an air fryer or slow cooker or both
Fresh pasta and pesto
Fresh store bought soup and cheese toasties and veggie sticks
Scrabbled eggs, omelette and veg sticks or cucumber, and cherry Tom's
Nuggets, chips in airfryer and beans, and veg on the stove
Pre-cooked chicken and salad
Chicken breast in the airfryer, steamed veg
Spag bol and fresh pasta (cook the bol. On Sunday when you cook Sundays dinner)
Burgers, chicken burgers in the air fryer plus veg or salad
Fish fingers or battered fish and chips plus beans and veg
Chicken and micro rice
Veggie sticks, hummus, pita, and delivery meats or pre-cooked chicken
Stir fry
Stews, chilli, curries, braised joints in slow cooker. Bung everything in first thing in the morning and set the timer.
Google 20 mins dinners for more variety. The above will take a maximum of 20 mins. Buying pre seasoned/marinated chicken breast helps, and you can also get tray bakes and other things from the grocery store.
One of my easy but takes around 40 mins is the marinated chicken in curry paste, add onions, Peppers and sliced carrots bake in oven for 20 mins add 1/2 can coconut milk and cook for another 20mins. Meanwhile, cook rice and veg. Naan in the oven while serving up and then take it out. We do homework and prep for the next day while dinner cooks.
You're doing really well. It will take you time to establish new routines and get use to prepping and shopping accordingly. If you have the occasional take out, no biggie. It's a fair bit to manage. Small steps.