Does anyone have experience in multiple retakes for prestigious unis?

I had a badly controlled autoimmune condition in my first sitting and got BCD that resulted in hospital treatment and long periods of time off school and I retook and got A*AC.

I missed one of my papers which is the subject I got a C in this time as I had a mental health breakdown the night of my exam where I spent the whole night blowing my eyes out, self harming and contemplating whether I should overdose as the domestic abuse I suffered genuinely made me feel worthless. I am currently estranged from my parents and have very little contact. I was already planning on taking a gap year to save up for university so was wondering how realistic it is for me to retake the subject I missed a paper in and got a C in.

I am intrested in studying something humanities related like Politics and was wondering how sympathetic admissions tutors are to people in my situation.