I remember hitting "the wall" when I got to college. The curse of being intelligent enough to basically walk through HS, never needing to study. Well, that's my excuse and I sticking to it.
I saw something today.
Why try to be perfect when you could be real.
Believe in yourself.
Where are you matriculating?

you can only do your best

FWIW, @Holyhellkel, when I first went to law school, I had sort of cruised through college. Good grades had come easy for me there, and I figured that I was able to handle any material with ease because I was so damn smart.

It turned out, everyone in law school was that damn smart. When first semester grades were posted, it took my breath away. I'd never thought of myself as having such poor grades. And I realized that I'd been using my senior-year undergraduate study habits, which were, shall we say, not the most diligent. So I had to step up my game.

I did, got very good grades the rest of my time in law school, and am proud of my overall transcript. But I needed reality to give me that firm, direct kick in the ass-essment in order to get me to up my game to where it needed to be.

I hope my story offers a lesson for you.

There is a lot more to a rocket than just the rocket propellent. So, 'rocket science' is literally more than just chemical engineering.

...struggle through the learning curve...remember, there really is such a thing! I once, felt that I was going to throw-up, in every math class! And, back then I did not understand it was anxiety! The anxiety, block my retention, so then I felt like a 'dummy'...which compounded the problem with learning math! Do relaxation before hard classes, it does help! Best of luck

Rocket science is also a whole lot of physics and engineering.

Just remember that all things can be broken down into simpler elements to be dealt with in turn. Also, there are few who can stay ahead of a subject, few who can stay abreast, and the rest are in a constant catch up mode. The trick, if you find yourself in the latter group, is to not let all of it come at you at once. One thing at a time and stay focused.

Forgot to mention, there is no replacement for good lecture notes to supplement material in the texts.

Tomorrow is the start of classes for me,too. The difference is.....I'm standing at the front of the classroom, delivering lectures about Audio Art and Audio Science. Here is what I tell my students:
" In order to get a good grade in this class you need to do three things"

1. Show up, on time, for class.
2. Pay attention during class, and take good notes.
3. Prepare for quizzes and tests by regularly reviewing those notes. Use the textbook and online sources to clarify anything that you do not understand.
   Asking questions before, during and after class of your instructor or classmates is also very useful.
   ( I know, that's four things, but I usually stick to the first three........}.

Way easier than Rocket Science.......

Keep your head up and don't give up.

Come on now do be down. You can do this. Focus focus focus. Just keep thinking how happy you will be when you accomplish your mission that's what I do. Ask your self how far did you get and how far you have to go. It seems your just fatigued. But you know the end of the Journey is the toughest part just like 3 mile run its harder at the end, and what do runners do run harder at the end. I hope I could give you some motivation. That brain of yours is magnificent if it got you this far. Keep up the pace. Good Luck.