salmon fillets 5 pounds,
mince meat 4,
kitchen roll 3,
fruit 2 pounds,
veg 3 pounds,
biscuits 3 pounds,
toilet roll 6,
dettol wipes 3,
frozen fish 5,
milk 1,
potatoes 2,
orange juice 2,
yoghurt 3,
pasta sauce 3,
couple of baby meals ready made 3
That's a hell of a lot of food for one adult and a small child for 2/3 days.
The mince would probably make 3 meals for the pair of you, plus there's the salmon and frozen fish too, so that's a week's worth of main meals right there. Fruit and veg fine, but £2 buys a lot of potatoes, that would last a week too. Plus presumably sometimes you eat pasta or rice instead.
If you're spending £18 a week on kitchen roll and disposable wipes, you have a serious problem. Use sparingly and wet cloths instead most of the time. We never buy wipes and get a 4 pack of cheap kitchen roll that probably lasts a month or two and we use most of it to wipe up after what the cats have dragged in. Likewise toilet roll, you don't really buy £6 worth of toilet roll every 3 days do you?
Pasta sauce - we only ever get the nice jars on offer, eg Loyd Grosman or Heinz so they're now about £1.50, so again I don't understand what you're doing with £3 of pasta sauce in 2 days. We get 3 adult portions from a jar so I would have thought one jar would feed you both twice.
You must either be throwing a lot of food away, eat more than anyone could think possible or have cupboards etc rammed with food.
Can you batch cook and freeze or use over the next day or two a couple of times a week? If you make something different each time you can get into a rotation so eat a variety of food?