YESS!!! Keep your studying to like 8 hours.... 5 is a good number... or I'm not sure if those number are right, but defiantly not more than that.
In the summer, spend like 4 hours a day or something learning how to learn. Get books on getting good grades. And do some research on goggle about how to balance things out.
Spend a day to go partying on Fridays... like you used to. Maybe even Saturday. It will keep you from being depressed and lonely, and it will let your brain recharge. Your DNA mandates that you be social or you will feel depressed. You will have fun. You fill find some friends that you can study with.
Its because your brain has not hard wired the concepts into your subconscious brain. Why? Because you've fried your hippocampus because of being stressed out and because you don't give a chance for your hippocampus to do its thing at night and send the new information into your long term memory when you sleep.
Effects of stress on learning
Its like a car engine, if its out of oil you'd better stop or you cause serious damage. Also because if you don't stop to fix it and you keep trying to drive it, then you are going to get nowhere fast.
You sound like you've been stressed the whole semester. I remember high school that I felt like I was getting dumber as the semester when on because the stress was taking its toll on my learning circuits.
It takes a little bit for your mind to warm up again. Or maybe because your brain was fried back then too.
Do some meditation before you start learning so that you are not stressed, that you are relaxed, and that you are having alpha brainwaves that are awesome for learning.
Also read this article
Read the whole thing.
Also from here:
But don't worry, it also goes on to say that it it quite reversible because the brain repair itself.