A lot of that was Greek to me, so I know for a fact I should DEFINITELY start over with simple arithmetic! LOL You know the weird thing is...I never did well when I had to "show my work". I would skip a step or two, and when I did, I would somehow arrive at the correct answer. When I had to show each step, I was sure to screw it up. Overthinking, I suppose. :)
You will be developing methods. At first it will be really simple stuff, but later when you get to methods of integration it will be very important to note exactly what steps you do when you solve a problem. Some methods are two-step and if you can just bang those out you will be at the level expected of grad students. That's why grad students don't solve problems so much as prove theorems; they are expected to know how to solve problems already.