I understood, OP. My teens have scouts 1 evening a week and a sport that trains 2 evenings a week (25 mile round trip each time) then a match at the weekend which is a 90mile round trip(!). I have 2 kids doing this in the same sport but different teams/age groups and it takes a lot of my time outside of work. We can't lift share because the training and matches are overlapping times for the 2 DC. DH has an awkward job, but he helps out with the driving about one trip in 4.
For each one
Sport fees £25/month + replacing training kit (average £10/month - I buy most of the expensive stuff on vinted)
Scouts £5-10/month
£30/month pocket money
£17/month mobile phone
School transport is free for us
They get £15/month on parent pay to buy lunch in the school canteen once a week. Otherwide they take a packed lunch and they make it themselves.
I spend around £120/month per DC (+ diesel) but I would also buy them some clothes and standard toiletries with weekly shop. If DC wants something particular that is beyond my budget or not sold at the supermarket, they have to save and buy it themselves, or wait for birthday /christmas.
Your big cost that you can reduce is the lunches. While lunch is an essential, yes, I don't see that it is necessary to buy it every day.
That is not a great habit to bring in to adulthood either. Preparing your own meals is a life skill and young men need to learn this skill or else they might always end up reliant on others to cook for them. I buy wraps (or frozen baguettes as a treat), chicken/ham/eggs, salad leaves, cheese, cereal bars, etc for the lunchbox and it comes to about £10 a week. Or in winter DC likes to make their own soup, stew or pasta meal and take it in a flask. That's even cheaper. We've found the Marcus Rashford & Tom Kerridge "full time meals" resource really useful for filling up hungry sporty kids, on a budget. The recipes are specially written so that teens can make them easily.
We are clear with the DC that there is a finite budget. Buying lunch instead of making it would mean having to sacrifice some of the other things we like to do, like trips away, or getting a chippy dinner after a day at the beach.
Just be honest and say you can't give any more (time and/or money) unless your son increases their input (e.g. lunch or organising a lift share, etc) or makes some other sacrifice to help reduce the time/money you're spending. Good luck op!