Is the £2700 before or after annual and irregular essential costs like car servicing/MOT/insurance, Christmas, white goods replacement etc?
If it's before, some money will go on these things and you'll need to make sure you put some aside to account for ups and downs in costs over the year. Also ideally so you can do things like car replacement without borrowing.
Do you have any savings and what are your pensions like? Do you have a mortgage and if so, has it gone up yet?
The problem with being used to spending all your money on non essentials is that you have no resilience. You probably won't be able to carry on your lifestyle in retirement and things will unravel very quickly if you lose an income, eg due to illness or redundancy. To be frank, it's utterly stupid to be in this position when you can afford not to be.
You need to budget and be honest about what are essential costs and what are extras. Plus you need to account for all essential costs, including those that are annual/irregular (school clothes/shoes etc, car maintenance etc, insurance, replacement of essentials like cars, white goods etc) and the 'what ifs' (illness, redundancy), before seeing money as available to spend on things like clothes and days out.
Have a look at Moneysaving Expert and do everything that is relevant. Set up standing orders to savings accounts for money that needs to be saved for irregular essential expenses then, once you have identified what money is truely spare, how about putting it into separate accounts (eg one for you, one for DH and one for family days out etc) to be spent on a 'when it's gone, it's gone' basis?
https://www.moneysavingexpert.com/family/money-help/