Stuck at 152Q/302 after 6 months. Exhausted GregMat, PrepSwift, & all Official material. Need help stopping over-calculation and managing time for a retake in 1 month!

Hey everyone,

I'm applying for MSIS programs for Fall 2027 and I need to get this test out of the way. I just took the GRE (first attempt) after 4 months of studying and got a 302 (152Q, 150V) I would have never reached this score without GregMat especially considering the fact that I had completely lost touch with Maths since 10th Grade (I'm in the field of Marketing and Advertising now pivoting into Information Systems) but it's still not enough. My goal is just a passable 155+ atleast (160 is the aim) in Quant (I'm fine with my Verbal don't wanna focus on it too much) so I can finish this hassle once and for all and focus on my work experience, project portfolio's, LOR's and essays. (Only 2 out of my target 12 universities actually have a prerequisite of the GRE but I wanna have an acceptable score for Quant because I do want to stand a chance of admission in them)

My Background & Prep:

• I scored 89/100 in 10th-grade math(that was in 2017), but I haven't taken any formal math courses since then.
• I am a regular GregMat user since October: I've taken every GregMat test and watched every single PrepSwift video that helped me actually reach the 152 which I thought was once impossible considering I haven't touched math and ETS questions are psychologically insane (something today's test proved terribly).
• I have taken EVERY ETS PowerPrep practice test (including the 3 paid ones)(Highest was in Powerprep 2 where I got 158Q and 150V).
• I've also taken all the free Kaplan tests. I literally have no fresh official tests left.

The Diagnosis (Where I'm messing up):

After analyzing my performance today, I realized I’m not failing because I lack the math foundation. I actually had time to do every question on test day(Which was something I learnt how to skip questions that I cannot crack in the first 60 seconds thanks to the Powerprep's), but I’m falling into traps because I overthink, over-calculate, and double-check too much. Here are the exact mistakes I keep making:

1. Over-calculating and Double-Checking: For example, a Quantitative Comparison question asked to compare 0.2x^2 and (3/7x)^2 where x not equal to 0. Instead of just cancelling the x^2 on both sides and cross-multiplying the fractions (which takes 15 seconds), I plugged in ZONEF numbers (negatives and fractions) to double-check my work. This wasted minutes.
2. Brute-Forcing Multiple Choice: ​ I got hit with a quadratic: 16t^2 - 192t + 135 = 0 with options like 45/4, 51/4, and -3/4 (Multiple answer question). Instead of using the "sum of the roots" ($-b/a$) rule to instantly find the missing answer, I panicked and tried to calculate every fraction in the on-screen calculator (which got me the correct answer but I wasted a minute or 2 more of mine).
3. Paralysis from Abstract Variables: Almost 6-7 questions asked are with abstract variables where the strategy is to choose numbers but it's so abstract that breaking it down in itself only took a minute or two more, an example was ​ line (p,r) is on the xy plane where pr < 0 and the slope is p. Instead of just plugging in random variables like p=2, r=-3, I tried to solve it conceptually in my head and froze.
4. The "Data Dump" Trap: I spent 3+ minutes trying to understand an 11-column Data Interpretation table in Section 1 when I only needed to look at 2 columns, which ruined my pacing(I was stubborn because I always get Data Interpretation questions correct).
5. Rushing Questions so that I don't miss an easy question wasting time on a complicated one: This is a rule I learned the hard way while giving the First Paid ETS Power prep but this also forces me to not break down a tough question into smaller bits of info and then start solving because the ambiguity forces me to just leave and randomly select some random option (the worst ones are QC with no numbers and only variables)
6. How to tackle Multiple Answer questions? - These are the worst types of questions that drain me the most, how do I tackle them in a faster, more efficient way (Need shortcuts to solve this quicker without overthinking if I correctly checked all options or not)

Current tentative Plan -

1) Redo all Powerprep Tests and even GregMat Tests continuously mimicking test conditions to forcefully train my brain to not collapse or get overwhelmed when the barrage of questions hit me keeping everything timed and to improve instant pattern recognition so that I can instantly identify and figure out how to solve the sum in not more than 60 seconds (easier said than done because it sort of feels impossible right now)

2)Revisit all Prepswift videos and go through the "I'm overwhelmed" plan videos from scratch solving all Tickbox quizzes without fail.

3) Practise all questions from the ETS official guide and quantitative reasoning guide (also timed) and maintain an error log which must be referred every single day

If there's anything extra that you suggest I do, feel free to do so

My Questions for you guys:

1. How do you build the discipline to trust a mathematical simplification and NOT plug in numbers to double-check?
2. How do you stop your brain from "overthinking" every answer?
3. How do you conquer the stubbornness to drop a question after 30 seconds while also making sure that you're able to break down the math in the first 10 seconds in which you see the question?
4. Since I have absolutely zero fresh official material left, what is the best way to practice pacing and "Strategic Surrender" (skipping hard questions) for my retake in a month?

Any specific strategies or drills would be greatly appreciated!