I am less than 1 month away from my exam.
MY SC reference:
MGMAT Verbal Fundamental
MGMAT SC Guide
Material prepared by a local instructor
VR2
OG12
OG13
After referring all of the above, and reading lot of posts, strategies, and blog posts, i attempted OG12 Q's from the end to start.
These 10 Q's are the ones which i answered wrong in my previous attempt.
I answered all of them wrong and took 14 seconds to answer

I m very disappointed and frustrated.
I know about meaning clarity, logic etc but i was not able to apply or was not able to identify the core problem with sentence.
I am non native speaker.
Though i can answer medium and easy SC questions with close to 90% accuracy, i am kinda giving up on hard SC Q's

Is there any hope of improving SC in say 20-25 days?
What am i missing and how can i improve?