First, thanks @StressedOutPa for mentioning my blog. Very kind.
@MeThenYouPlus4 Reckon it would help to change mindset.
As you've identified, all those little spends each day can be a killer when money is tight. My suggestions is to assume you're not going to have any spending money beyond your bills. Zip all. Zilch.
Then only add back stuff that seems really essential, and look for free or lower cost alternatives wherever possible.
I focus more on the kids, so can see why £6 for soft play would appeal, especially in this weather. But I'd take drinks, snacks & something to keep the kids occupied if bored, so I didn't have to spend any more. I'd also look for cheaper alternatives other days (eg library, museums, parks, galleries, visiting friends, country walks, baking or den building at home, gardening for kids in better weather).
Don't buy anything without thinking "is this helping me stay around for my son, rather than working more hours?" Suspect £5 honey wouldn't pass that test. Sounds like you're tempted to spend when you're in shops, like the craft fair, charity shop or extras during top up shopping in the supermarket. If you know that - don't go into shops! Start meal planning, write a list and stick to fewer, bigger supermarket trips or order online. And unsubscribe from marketing emails while you're at it.
Also, I swear by keeping a spending diary and writing down every single thing I spend. Makes me much more aware of all the little things, so I'm less likely to buy extras like sweets, sandwiches, charity shop hauls, magazines or whatever.
If you're used to spending more, I recommend shopping from the contents of your cupboards first, as you might be surprised what you already have.
So make meals based on the contents of your kitchen cupboards, fridge & freezer, then only buy extra ingredients needed. Rifle through your wardrobe so you can re-wear stuff you already have rather than buying new. Go through all the kids toys, games, DVDs, craft kits etc, then play them all over again before you buy anything more.
Find anything you don't need or want any more? Sell it. Obviously the stuff you already have won't last for ever, but might get you into the mindset of spending less.
Anyway sorry this is a bit long, hope some of it is vaguely helpful and good luck!