how to study through burnout?

So I need to rant for a sec and I really really need advice.

So I'm not going to school anymore due to mental health, I'm doing external prep for my exams and due to good grades I was even able to skip a year and do my exams a year early.

But now they're next month and I'm so incredibly overwhelmed, I study every single day, for months now I've been doing that (4-14 hours a day) but I'm so burned out.

I try giving advice on studying and stuff on here and post stats to motivate myself but Jesus.

Ik it will be over in 2 months but man all I do is cry. I can sit myself down and study easily and I do understand the materials but I don't know what to do anymore I'm scared if I keep going I'll get worse again.

No one's forcing me to get good grades, no one's telling me I have to pass but I don't have anything else other than good grades. I don't have a social life, I'm not good at anything and I don't want to be dependent on my family anymore.

I need to be the top student because if I'm not I once again am just average.

Can someone please give me advice how to work through burnouts I do nothing but study, even if I am not actively studying I don't do anything where I don't, in any way, prepare for theses damn exams