if you want to set a budget
then from your expenses you can't change the mortgage, utilities or council tax
but you can change the sky, mobile phone, internet, grocery shopping so those are the items you can budget.
Start by by reducing the budget for your food shopping. Look at buying an 8th meal for the week of store cupboard items for the last week of the month to make.
The takeaway foods bills is something you can also reduce, use fake takeaway meals instead. Or simple fish from the freezer department with oven chips for fish and chips meal, pizza the same as its easy to cook in the oven and add garlic bread etc as an alternative to a take away.
budget for £20 less per week for the groceries
try telephoning sky, mobile provider to reduce the bill, see whether it works. Look at sim only deals that are far cheaper, fire sticks that are one purchase and get rid of sky for example and not have £150 on phones and tv package
stop spending on things you don't actually need, but set yourself a small sundries amount.