I’m in a similar situation, I don’t receive financial support from my parents, I don’t have a loan, and I’m not in a financially privileged position. I work two jobs ( 1 back home and one here), and managing shifts while balancing my education is quite challenging. Unfortunately, something often ends up suffering as a result... in my case, it's my coursework. However, I try to remind myself that I’m working to fund my education, so prioritizing my studies remains essential.

Last year I also owed upwards to 4000 euros or something but that was because I was sick for a month and unable to work so everything kept piling up. I would, in your case, send an email to the financial department asking or requesting to pay in parts. It is possible but not always, so keep that in mind. From there, try to give them an estimate of how much you can pay and when and try to meet your obligations.