You seem exhausted, worn out and worked to the bone. I get it.
However, the anger you have ought to be directed at the broken system that is student finance, not your girlfriend. I truly can comprehend your frustration, but she is not the one causing your situation. You're jealous, and that's understandable, I think most people would be. She may be saying things which are upsetting you, and would perhaps upset a lot of people - such as not being able to work while at university, and you need to communicate this with her.
Not when you're already annoyed. You need to do it when you're calm and in a non-blaming, non confrontational way. A simple, "hey, when you say xyz it makes be feel like abc. I know you're trying to help but I would prefer in the future you didn't say that."
I somewhat get your situation, not to the same extent. I go to uni full-time and work full-time on breaks. I work 20+ hour weeks during term on top of a content-heavy course. My partner wants to spend all of his free-time with me, and whilst I appreciate it so much, I don't have that time. Or I find myself giving in and then getting behind on university work.
My partner does a degree-apprenticeship so he works from home 4 days a week and goes to uni for one. All of his tuition is covered and he gets 21k+ a year from his company. I find myself jealous of him often, but I know that's not his fault, and I'd never take it out on him. He has said things in the past which upset me, like suggesting I just work less if I have no time or to schedule my academic work better so I have more time to spend with him without getting behind.
I told him how saying these things made me feel. I can't work less or I won't have money. I can't schedule my academic work better because I'm entirely burnt out from work and cannot do any academic work on the same days I have paid work. He understood immediately. He was very apologetic and we have set up boundaries which make it work. We spend one day and night together by default, and if I have all of my work completed, then we can hangout more. He also has never said the aforementioned things since I told him how it made me feel.
Setting up a boundary like this with your girlfriend may help you.
I get you're tired. But it's not her fault. Communicating can and will do wonders if you're both willing to be serious about it.