Sorry to hear that you are feeling upset these days. It’s said that the college endurance examination is coming. I know you have much pressure.
You said you didn’t stop studying until at midnight every day, as a result, you couldn’t focus your mind on the study the next day. You felt tired, what’s worse, the effect of studying was low.
Why not stop your step? Sometimes, stopping to have a rest maybe the best way to relax yourself. From my point of the view, health plays an important role in studying. As long as we have a stronger body, we can overcome all the difficulties. Of course, you should often go over the knowledge, especially the points which you don’t understand.
Believe yourself and do everything with the hope of being successful.