Easy OP. I do that every week, shopping at a big Tesco. I feed me and ds (16) who eats more than I do. You'll be fine, Basic suggestions....
Breakfast :
toast, marmalade/jam/marmite & satsuma/pear. Coffee, water
Lunch:
Beans on toast,
Cornish pasties & frozen sweetcorn
home made veggie soup and crusty bread,
fish fingers, peas and oven chips.
Cheese & beetroot/tomato/pickle sandwiches.
Sausage rolls and beans
Broccoli & blue cheese soup
Tinned sardines with warm boiled potatoes and fennel
Supper:
Sweet peppers stuffed with parslied sausagemeat, with garlic bread
Wholemeal spaghetti with meatballs and homemade tomato sauce
Breaded cod with peas and chips
Chicken fajitas with lettuce and tomatoes, creme fraiche and spices
Cassoulet made with cubed pork shoulder, garlic, tomatoes, onions and cannellini beans
Cheese and tomato/spring onion omelettes and oven chips
Home made mushroom risotto with grated cheese
Fusilli putanesca
Casserole of chicken thighs with onions, green olives, lemon, with brown rice
Seafood risotto made with frozen hake, frozen mussels and flavoured with garlic & fennel seeds.
Roast gammon with roast potatoes, couscous and peas/broccoli
OP, you don't have to reduce quality. I'm post-cancer and eat 30+ fruit & veg a week as part of my efforts to boost immunity. A bit of thought and you'll manage.