I'm sorry this test is giving you trouble—you're not alone!
First, could you check your score for me for your 4th test? A score of 555 is not possible (the scores are always in 10 point increments). Did you score a 550? (I'll assume so for the purposes of this post.)
Next, I notice that you had your highest Q score (35) on the 3rd test and your highest V score (36) on the 4th test—so one task is to figure out how to get you your highest Q and V scores on the *same* test. Getting those two scores on the same test would put you at a 590, so we're going to assume that that is your general scoring level now in terms of ability. (And given that you're going for a 650, you're not actually all that far from where you'd like to be.
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Next, I'm also noticing that your top V score does represent a nice jump from your starting point (28 -->36 nice work!) but the same is not true on the quant side (34 -->35). So I also want to figure out what's going on there.
Here's one thing to analyze: Look at the mix of difficulties you earned on test 1 and compare that to the mix of difficulties you earned on tests 3 and 4. Are you earning a harder mix of questions, even though your score didn't change much on test 3 (and went down on test 4)? If so, you should see the pattern that you were earning a higher score at some point earlier in the section but that your score dropped by the end of the section. That kind of drop occurs due to timing or mental fatigue issues (usually a combination of both). (The timing piece can be going too slowly or too quickly, or it can just be misallocating—so you spend a bunch of extra time on some questions but then rush others to make up the time, so you mostly look like you're on time, but what you're really exhibiting is "up and down" timing on individual problems.)
The next thing to analyze is the difference across the sections between tests 3 and 4. In Q, what happened differently on T4 such that your score dropped 5 points? Again, could have been a timing or mental fatigue issue that caused a drop by the end. You could also have had careless error or holes in your foundation steadily throughout, such that you just never raised your score as much in the first place. Or you could have had a bad string somewhere—a lot of questions wrong in a row. That can put you in a deep hole and then you might not have enough room left to climb out of that hole.
Ditto on V, what was better on T4 that allowed you to pick up 6 more points compared to T3?
Next, this may also be part of the issue:
I worked through each section on a rotational basis (for example: one day 16 PS questions + 16 SC question then debrief in the afternoon, re-do the questions I got wrong until I got them right in around 2 minutes, the next days 16 DS + 16 RC or CR or SC, rinse repeat)
The doesn't mimic the real test in a couple of ways. First, the real test will never give you all of one type in a row—you have to jump around among question types in a section. That's harder—imagine playing tennis and you only ever practice hitting 16 forehands in a row, then 16 backhands. You know exactly what's coming before the other person even hits the ball, and that gives you an artificial advantage. So then, when you play a match, you're at a disadvantage because you haven't practiced learning how to be open to anything and just reacting once you realize what you're going to get this time.
Second, you mention redoing the questions immediately until you can get them right in 2 minutes. But on the real test, you're never going to have just done any of these problems—it's not like a school test, where you're given problems to practice that are almost identical to the ones you'll see on the real test (and where that kind of study style might have worked better).
The problems you're practicing aren't almost identical to the ones you see on the real thing. The ones you see on the real thing will often look quite different on the surface. What you're really studying when you study these problems is not how to do this one problem in front of you right now. You're really studying
how to think your way through a new problem, using this problem as a tool or guideline. So when you're studying, ask yourself things like, "How do I know to approach it this way? How should I know that this answer is likely a trap? How could they change some details of this problem to make it harder—or easier?" etc.
It is still a good idea to redo some OG problems—but I would only try them again immediately after (ie, same day) if there was a different way I wanted to try solving. If I just wanted to redo it the same way to see whether I remembered, I'd give myself one, two, even three weeks—basically give yourself time to start forgetting and having to force your brain to recall that memory again. That's what you actually have to do on the real test: recall stuff you learned days or weeks earlier.
Let me know your answers to my questions above (and really dig into that data / take your time—you can use that article that talks about how to analyze exams to help) and we'll figure out where to go from here.