Don't compare yourself to others. Just because they appear to be doing well doesn't mean they are - they could be mortgaged to the hilt and maxed out on credit cards!
Regardless, you've set yourself a target to pay off your debt which is highly commendable. Write the amount outstanding in bold figures on a piece of paper and put it on the inside of a cupboard door where you'll see it regularly. Once a month, replace it with the new, lower figure and congratulate yourself. This will keep you motivated and on track.
As others have said, look out for good quality second hand. This doesn't necessarily mean they've been worn. I regularly search Ebay for new/unused goods. Last year, I bought a pair of new, still boxed, leather Clarks shoes for work for less than £20 in an auction (RRP £70.) My biggest bargain though was £5 for a Woolovers 100% British Wool Aran jumper, in its original packaging and with tags on, again in an auction (RSP £65- £70.)
I also find Amazon is a good place to bulk buy branded detergents at cheaper prices than the supermarkets.
I keep back a small amount of money a month for supermarket special offers and stock up on anything with a long shelf life that I use a lot of.
I personally don't see the point of regularly replacing cars. My motto is buy the best you can afford, keep it well serviced and it should run for years. My last car was 18 years old (Honda) and still going strong when I part ex'd her for my newer one.
I really don't understand why you look down on Aldi. There are all kinds of gems to be found in the middle aisle and at excellent prices. I'm still using an Ambiano glass kettle I bought pre-Covid and I had one of their large dehumidifiers, which despite heavy use, lasted 7 years. I buy most of my weekly shop there and find the quality is mostly as good, if not better, than other supermarkets.
One final tip. Replace shower gel and handwash with good quality soap (get some silicone soap savers.) I did this to reduce my consumption of single use plastic and it has had all kinds of benefits. I use Italian Nesti Dante soap, which is not a cheap brand, but it is very cost effective. The bars are huge so I cut mine in half with a soap cutter (£5). The scents are gorgeous and last right down to the last little bit. They're triple milled, have no nasty chemicals and leave your skin lovely and soft. Also, even allowing for the price per bar, I am still saving money by not buying bottles because the bars last such a long time. Limonum Zagara (Italian lemon) and Portofino are my favourites for showering; the Olive and Tangerine one for hand washing. Amazon and Notino.co.uk have the best prices.