Other people have suggested this but what I do is write down everything that goes out in terms of money and I mean everything.
All of your major bills are easy, they might even be directly taken out of your bank account so you know exactly how much those are,
But I'm talking about every single time your physical or digital wallet opens and I mean for a coffee, a treat, donation rounded up at the register for charity, a lotto ticket, anything.
That part will be hard to remember to write down because you sometimes forget, but write it on your hand or in your phone as soon as you pay something unusual.
And then write it on a big piece of paper when you get home maybe in the kitchen. By date. Just keep a running tally of everything that goes out.
Chances are you'll still forget something but at the end of the month, you can go through and you can find out where the money went.
No, you might have some subscriptions or other online leeches that you forgotten about, some of which may be completely legitimate like you might be paying for cloud storage photos or online antivirus protection, stuff that you've been doing for years and you forgotten about, you'll have to do a little more research to find those once a year recurring subscriptions that have flown your mind.
Additionally I believe that there are some online services/apps that you can utilize to help you find these subscriptions that you're paying for that you might have forgotten about.
Money that comes in is important, but money that goes out is equally important.
And it's really easy to know how much money comes in. Typically as you mentioned that is your monthly wages and your child support. There is no other money coming in.
But the money that goes out is fugitive, it goes out in big things it goes out in little things it flies out seasonally, that's what you got to try to figure out where it's leaking from.
And I can't tell from your posts if your parents are being a pain or if they are trying to show genuine concern. Perhaps a bit of both. Well I do believe that they are correct in saying with the amount of money that you make and the amount of people you're supporting you should be able to have some money left at the end of the month, don't consider yourself to be a financial failure just yet. You've just got to figure out where that extra money is going. You've already accounted for about half of your income and you can't figure out where the other half's going so that's what you got to figure out. But congratulations for having us be concerned, something that you're trying to fix, and also having no debt at the end of the month. Cuz that's great.
(Edited because I forgot to add, you already know that you're paying for sky service and you say you don't use it, but you're paying every month for the equipment which you haven't returned yet. Well that's already a pretty big red flag to me, there must be other things like this that you've just forgotten about or you think are too much trouble to go after, and they're bleeding your wallet.)