I think the reality of life, whether you have 50k or 150k a year, is that you have to budget and at times you "scrape by" depending on your lifestyle choices.
Looking at the choices we made when our 3 DC were young are pretty much the same choices we make now, even though they are all in their 20's and nearly independent. So:
No takeaways. Eating out is for birthdays only and we look for vouchers/restaurant deals.
Days out are doing free things, such as meeting with friends, going to the seaside, walking, etc.
Clothes are all charity shop or car boot (both for ethical reasons and for cost). NCT sales are brilliant for young children's clothes. Supermarket clothes are expensive and have little re-sale value. If you buy a decent make second hand, ie Boden, if it's in a reasonable condition it holds its value and can be sold on for pretty much the price you paid for it.
You can reduce your supermarket spending by shopping in the evening when items are reduced. When the DC were younger, I would go almost every evening to buy the reduced items and fill the freezer, now it is just a few times a week (it has become a bit of a hobby and a challenge!). Also, growing some of your own fruit and vegetables, keeping chickens (if you are able to), collecting cherries, apples, plums, blackberries etc and freezing them, batch cooking soups and stews can all massively cut your food budget.
Holidays were once a year camping, otherwise weekends staying at grandparents and occasionally tagging along with one of DH's work trips.
It is question of priorities and you are in a position where you do have some flexibility in your spending where many people don't. Education, activities for the children and having animals were and are more important for us than takeaways, new clothes, expensive holidays, and big supermarket spends.
The more activities you and your children are able to take part in the more entertainment you will have as a family such as sports matches, swimming galas, plays and musical concerts, art exhibitions, maybe even horse events - that would certainly bring some excitement into your life OP!