You Need a Budget app. It’s basically envelopes:
imagine you got your monthly salary in cash, and you’ve got a stack of envelopes. You have envelopes for:
Rent/mortgage
Transport (public or petrol)
Savings (for emergencies)
Savings (for specifics eg annual MOT and car stuff if that applies and you know you won’t have it in one paycheque)
Food
Gas
Electricity
Water
Council tax
Internet
Phone
Contact lenses or other subscriptions
Insurance
Toiletries
Going out (including birthday cards, gifts)
Christmas (easier to save a little each month)
Free spending
Divide up your cash salary into the envelopes, starting with the “you’d lose your home or go to prison” ones – roof over your head and council tax. Then cash into the gas, electricity and food ones. Then into internet, phone, insurance and subs. Then savings for annual things like TV licence, MOT, etc. Then anything left split as you will into an emergency savings pot, going out or hobbies or things you know you will want to spend on. Anything left (unlikely) goes into free spending: the coffees and chocolate bars and top-up shops and snacks and taxis and stuff that bugger up most budgets. You’ll realise in this envelope exercise you have very little to spend here once the real bills are paid, but in life most people free spend and then consider the real bills afterwards. And then turn to credit.
Obviously these are metaphorical envelopes but loads of apps will help you do it.
Finally, consider: no spend September and other social media thingies that hold you accountable, library instead of bookshop, free hobby like walking instead of the pub, etc. Go for a night out with only the cash you have, not a card (assuming you have a safe means to get home): stops you going on to dinner or karaoke or the club you can’t afford. Set a savings goal. Take Apple Pay and Shopify off your phone, delete Klarna, lose your PayPal password, change your Amazon one then forget it or delete your account, make it hard to buy shit online.