My mental age stopped growing

Im in 10th grade now and im about to take a very important exam in a few hours that will determine my whole life.
And I haven't learned anything. I just can't accept that a few papers will determine my future. Everything feels so stupid and I can't seem to concentrate. I haven't touch my books in 6 months and my mental health is not doing well. And don't think i can ever meet my asian parents expectation.

For the past few years i haven't studied properly, its like my mentality is stuck in 7th grade. I just go with the flow. I stopped trying hard for anything.