If the "standard" ways of studying do not work for you; ditch them and invent your own. I had to rewrite a paper 3-4 times to get my grade up, getting it more "right" each time (and it was supposed to be rehashing exactly what the book said without plagiarizing) and on the third try I was so bored/disgusted I spent the entire weekend writing it (5+ pages) in verse

I rarely read the textbooks for courses; I just went to online sites about the subject and read and commented in my online classroom and in my own spaces/journals and asked my own questions and wondered things and answered my own questions and wrote little blurbs answering questions from the book/sites, etc. When it came time to write a paper, I knew what interested me, I'd found some off-the-wall interesting/difficult aspect of the subject (I often bought the professor's doctoral thesis, quoted from it and then refuted what they'd said :-) and wrote a wonderful thesis statement then had at it, easy as pie (especially since I was required to write 3-6 papers a semester usually; it was an online university so everything was written).

I suspect you did okay in the final because it was "final" and you'd lived through the course and remembered all the stuff as you wandered through. Sounds like you are better with "whole" things instead of one thing at a time; lots of people I think study for a test and don't see how that information applies to the next bit! They more or less forget the first bit, learn the second bit, forget the second bit, learn the third bit and then are in trouble when they have to have an exam on all three bits.