I'm a minimalist/ against excessive consumption. I consume high quality, long lasting, ethically made items in low quantities. For example I own 7 pairs of socks, 7 pairs of knickers, 3 PJ sets, 1 coat etc, and replace them when they are knackered, but don't increase the quantity. People think I am well dressed as my items stand out, but when they find out how little I own, they think I'm a bit nuts.
However even to me your situation sounds a bit extreme. What if your 1 pair of jeans gets ripped and other bottoms are in the wash? If you've had an intervention, it really must be quite bad. People at work wouldn't tell you. You do notice of someone turns up in the same pair of jeans every single day.
I presume you are in London/ another high cost location?
If you're worried about money, make a proper budget. On 3.7K, I'd like to hope that you are paying off 1K+ of the debt monthly. Is it possible for you to reduce the interest rate to 0/ lower rate? Are you saving as well? Saving rates usually aren't that great compared to interest rates, so would recommend paying off debt over saving too much.
Regarding clothing, what do you like?
Even premium high street brands like Reiss, Ralph Lauren, Me&Em etc sell for very little on Vinted. If you don't want used stuff (although much of it is with tags on!), have a look at sales (now on). Again, I'm not sure about your likes and budgets at all, but if you prefer nicer stuff, put 100 GBP aside to buy something every 3 months. That's 33 pounds a month, the cost of a few days' commute... Surely you can afford that if you think about it?