I can’t afford to pay this on my current wage – what can I do?

me my ex have a 28 month old daughter! we split ix October last year. after split i was paying 100 a week and still buying items of clothing and food etc. that £100 was for every week till about February cause i couldnt afford it!

it is now 50 a week and i seem to struggle still but i want to go down the correct path cause i was giving cash! also i gave my ex £1000 out of my tax rebate! i am on £100 a day before tax but work isn’t always contant!

i have fuel for my van which is £50 a week minimum, tax £121 for 6 months, maintenance cost for the vehicle, insurance £180 a month, rent £100 a week, then living costs!

can u please help me and advise