How the absolute f*ck am I supposed to pay for school?

To make a long story short I’m 20, and live on my own in my own apartment. My mom has passed away and dad is well, ✨not a citizen✨ and also does not pay any taxes (making it impossible to use him for FAFSA). my college is requiring me to prove I don’t rely on him financially (by proving lack of contact or financial support etc) which be a lengthy process within itself. I’m so incredibly stressed and am afraid I won’t be able to enroll in school this upcoming fall. I can’t even sign up for a payment plan , because I owe my school $600 which i absolutely cannot afford to pay. I legitimately don’t know what to do, I’m terrified to take out loans as I already have about 3k in medical bill debt.