I remember studying until I forgot. It’s normal.One year I had 4 final exams on one day - it was a real “Jesus take the wheel” moment…

Attention takes cognitive energy, and once that energy is depleted you go stupid.

Best practices: -Sleep around 8hrs, mandatory, helps with memory consolidation,error correction and resetting the battlefield for next day ( see “Why we Sleep” by Mathew Walker of Stamford).

-Exercise or vigorous activity -break a sweat -it’ll refresh the neurochemical soup in your brain.

Sugar snacks and caffeine before and during studying - brain uses a shit tone of energy and it loves glucose, and the caffeine does some Dopamine stuff that helps. Spread it out through the session, don’t smash it upfront and crash an hour later.

-Creatine monohydrate supplementation 20grams/day will supercharge your cognition when burnt out/sleep deprived- plenty of research on it- it’s a precursor to ATP and brain loves it some ATP.- check out the studies/protocols on it.

Other things Nicotine gum- boosts memory.

Modafinil /Adderall and Vyvanse etc… get your dopamine roaring- spiking focus, cognition and memory- but they are like flipping a switch. But be mindful of state dependent learning, dependence ,legality, clean supply etc.

Yes.

Yes, it’s common. If you have the time, I recommend spending a day or two just literally doing nothing stressful, giving yourself permission to relax and not work. Or maybe an afternoon. Or any hour. Hell, a single minute, or one single good inhale and exhale. Imo, the best way to do this is to go out into nature where there are few people around, and just have leisurely walks or maybe read a fun book under a tree. Or else spend the time with friends, sitting on the porch in the sunshine drinking tea or coffee and chatting. Avoid electronics devices or driving vehicles (especially in traffic) as much as possible. If you don’t have the time, I recommend trying to find some time to do this after your exams, before your next semester begins.

Imo, it is good that you anticipate re-taking the course next semester. Now you get to study and take the exam as if it is just practice for next semester.

Also, as you study, my bet is that you will find the concepts come back to you faster than you learned them the first time. It is quite common for us to forget how to do things, expecially things like academic math which is seldom used outside the classroom. We remember things more easily when we learned them recently, when we repeat them more, and when we can relate them to other useful and important things in our lives. Hence why I could probably tell you the exact order of operations dor disassembling and reassembling a motorcycle clutch, but I could only tell you that the Hamiltonian has something to do with matricies.

Remember that the most important thing you’re learning is that you can do hard things. Look at you, right now, burned out and feeling terrible, but still giving this exam your best shot! Knowing calculus, passing this class, getting good grades, getting a degree - those are all nice. But what will really help you succeed in life is exactly what you are doing right now - perservering. Trying your best even when success is far from guarenteed. Remember, you have to be the hero in your own story, and it’s not a good story if the hero never struggles!

Take a deep breath, accept the fact that you are stressed, accept the fact that remembering this stuff is difficult. And then try to appreciate the fact that you’re showing a lot of character by doing something so difficult. Be proud of yourself, and get back to studying.