Going from being fairly comfortable to being frugal every day of your life is uncomfortable and time consuming, but I think you can do it. It takes a whole new mindset! I would recommend spending a bunch of time on the MSE Forums. Specifically, I think there are debt/mortgage free threads/sections on there, where you'll find there are proper hardcore savers.
I think sometimes you have to think outside the box a bit. Yeah you've mentioned coffee, that's an easy one that we all know, but what about giving up the family car (for a few years) and having the most reliable school run mum/dad take your kids to school - with the incentive that you PAY them? (appreciate neurodiversity might make that hard).
What about renting out your garage/drive/both if you live close to a station (again, idk if renting a room as an office would work for neurodiverse kiddo)?
Everything you'd ordinarily give away - a potted plant, some not-perfect-nick pillowcases, SELL.
Cancel all subscriptions - podcasts, streaming. Only have one running, binge watch for a month, cancel, go on to the next.
I got rid of my Amazon Prime subscription in February - we were holding onto it because we live in a village. I haven't once missed it. I just buy less and plan more.
Paying £45 for broadband? Go down a package. If you don't have teens sucking up bandwidth with playstations, ipads and mobiles, chances are you can cope with 56mbps.
Got a garage full of really good tools? Advertise renting them out at a daily rate (with a sizeable cash deposit, obvs).
Rather than the coffee, get in your head the prices of everything you buy in a supermarket across all five of them. Just because people hear Aldi's cheap doesn't mean it's cheapest for everything all of the time. Again, it's time consuming and I don't exactly like doing it but we generally go to two different supermarkets once a fortnight, so four different ones across a month, and I won't buy anything at supermarket x that I know to currently be cheaper at supermarket y - we will either go without, or make other plans.
Kids needing stuff. Got that, it's tricky. I was in whatever we could get down the high street for a decent amount of money but never what all the kids were wearing or aspired to, and I don't remember emotionally suffering for it.
Bought something that's crap that you've opened? Take it back. I took £120ish worth of bedsheets, x2 washed and with no packet (plus x2 unopened) back to Tesco in January on day 27 of 28 on the receipt and the woman didn't even bat an eyelid. In fact, she apologised that they didn't meet my quality needs!
Those are just a few examples off the top of my head.
I believe the benefits for you far outweigh the sacrifices on your time. But I also believe that a bit of guidance and encouragement from MSE and possibly other forums (Reddit?), you'll absolutely have this nailed, OP.
Wishing you much luck and sending hugs.