Without the teenagers and eating a vegetarian diet you can do it. With the teenagers and wanting to eat meat I am not sure it is possible.
Me and DH are vegetarian and spend around £40 a week on food, toiletries and household cleaners.
I use an eco egg for washing. I bought it on ebay for about £10. It does around 70 washes I think and mine came with 3 extra packs of the pellet things so 280 washes for £10!
If clothes are very dirty or stained I use washing liquid but that is not very often and I use washing liquid from Lidl.
I buy the Original Source shower washes when they are on offer at 99p or £1. Me and DH shower every day but one bottle lasts quite a long time. I buy big bottles of shampoo in Home Bargains and, again, I wash my hair every day but it lasts months.
Nicky toilet rolls in Home Bargains are around £4.99 for a pack of 18. I think they are just as good as the dearer brands.
Washing up liquid is cheap in Lidl or Aldi. You really don't need loads of cleaning products. You can make your own or just buy the spray cleaners at around 50p each in Lidl or Wilkinson, one in the kitchen and one in the bathroom. I use them on the worktops, cooker, shower, basin, kitchen sink. I also have a cheap toilet cleaner and spray polish. That is it.
Are you still able to stock up? I would buy big bags of lentils, chickpeas, beans, pasta, rice etc. If you have an indian food shop anywhere near that is the place to buy them. Much bigger bags for much lower prices than supermarkets. Also their spices are much cheaper.
Don't bother stocking up on ready made sauces. Much cheaper to make your own in bulk and freeze.
Go to markets when they are near closing and they practically give away the fruit and veg. Buy frozen fruit and veg in places like Farm Foods or Iceland where they are cheap.
Buy bread when yellow stickered or on offer and freeze it. If you see milk that is yellow stickered buy that and freeze it. Always look at the yellow stickered items. The Morrisons near me reduce their fruit and veg to silly prices. I buy things like carrots, runner beans etc, cut them up and freeze them. Fruit can be frozen too.
We don't have a boring diet at all. We eat lots of eggs but only buy free range.
We eat things like: egg and lentil curry, sweet potato and black bean chilli, lentil bolognaise, veg and lentil shepherds pie, spicy chickpea pasties, mushroom stroganoff, beetroot pasta, veggie sausage pasta bake, chickpea and spinach curry, ratatouille and crusty bread