Can completely relate because this was me in my early 20s today, exactly the same story - I NEEDED to spend, it was such an urge. And as a result I never had any money. Even though your parents have tried stopping you you still spend. The problem lies with you, in order to change you need to change your mindset first. Just like with any addiction, you can only stop when YOU decide you are now ready to stop.
You need to force yourself really to go cold turkey, thats what I did. Sort of like taking a sip of something but then spitting it out, you need to walk into a shop, hold the stuff you want to buy but then place it back down and walk out. Even if it drives you insane, say No to yourself. Get a feel for the stuff but refuse to buy it. Then start saving the money in your house, thats when it puts into perspective what you've achieved. First you will save a couple of pounds, then you will save a whole £20 pounds. Then that 20 will turn into 40 and then 60 and then 100. When you're holding your first SAVED 100 pounds in your hands you will know that you HAVE the ability to abstain and say no and then it will turn into a challenge, lets see if I can get to 200 and then 500 and then 1000. Be warned though, there is a good chance you will go the other way and go from being a spendthrift to stingy, again thats what happened to me but only for a short while thankfully. When I saved together my first 10k I started having a better relationship with money, a good balance. And now I live within my means but of course spoil myself on occasion.
Anything is possible when you put your mind to it, you've got this ok! Starts by just saying NO.