going through it

I (26M) have been dating my girlfriend (26F) for nearly a year. at the beginning and up until recently it has been the best and most loving relationship I’ve ever had and I thought I’d truly found the person I’d been looking for.
then crap happened
she fell into a depressive state, tbf she has a ton of problems going on at home (she still lives with her parents), and just like that, although gradually, it took away bits and pieces of her. I have been trying to be as supportive as possible, while also trying to not get dragged down into it (due to this happening in a previous relationship), going to visit as much and as often as I can, since she lives 4 hours away. this means i’m there every other weekend, and those days i can never get anything done cause there no room to study.

cut to the end of may til now
I’m writing my thesis, and I don’t have much time cause I have to submit it next week to graduate, so that’s basically all i’m doing: either writing, or going to the hospital ward where I’ve been doing my rotations. she knows i’m busy, we text and chat everyday but i’m just too tired to call or facetime.

so the arguments have started, the ones where she feels neglected or not taken into consideration, ones where she get offended if I go to bed when she still wants to chat. and i’m angry.
angry cause I never have any time for myself, or to see my friends, or to do things i enjoy, or to sleep most nights. but she has all those things.

I don’t know how to communicate this to her and i’m so worried for the future, the one where i’m in the hospital 12 hours a day and I come home to someone who only tells me how much she wishes I was with her when I can’t be. it all feels so heavy

TLDR: I don’t know how to talk to my girlfriend about being overwhelmed by my thesis and her mental health taking a toll on both of us