GMAT Study plan for retake: analysis of study strategy (need help!)

Hey guys,
Hoping you could help me!

I just finished my first actual GMAT. Despite studying for about 3 months, my score has not improved. I am definitely doing something wrong. I was hoping you can help me understand what it is. I don’t want to waste time and make the same mistakes.

I have been studying since the beginning of march.

Below are my scores from mock tests:
GMAT Prep 1 (march 5): Q35, V17 (450)
Man Cat1: Q22, V33 (480)
Man Cat 2: Q37, V28 (540)
Man Cat 3: Q26, V32 (490)
GMAT Prep 2 (may 27): Q24, V23 (420)

Actual GMAT (May 29): Q30, V22 (450)

Materials used:
-Foundation MGMAT (Q and V): I realized early on that since I have been out of school for 10 years, I needed to build my base.
-Manhattan Books: Number properties, Algebra, CR, SC
-Took a review class prior to studying on march, but majority of the students were fresh out of university. I couldn’t keep up.
-OG 12 and 2016: I do problems before reviewing from Manhattan
-Created an Error log: but I think it could be more detailed. (I just write why I got it wrong)

Majority of my studies have been foundations. Building my based on concepts I forgot.
I do solve OG questions, I do my best to understand and learn from each problem.

Weaknesses: DS, RC, SC
Strength: CR

I’ve been reading the forum and I must say I’m slight overwhelmed. But if I have about 3 months to study till the next actual GMAT, what should I be focusing on? How should I be studying? I can do about 3 hours a day on weekdays, and 4 hours on Saturdays. My goal is at least 650.

Initial ideas to recalibrate my study plan (let me know what you think):
-Better Error Log?
-At this point, since I believe I do understand foundations, should I be just solving from OG only?
-I read somewhere that instead of solving out problems, I should be analyzing answers immediately, so my brain understands the right way of doing things, instead of how difficult it was the first time around.
-Analyzing the problem: why this answer is correct and why the others are wrong. Understanding if this is the fast way to do it
-Read more books to improve my ear?

Other resources: I have about 3 more CATS from Manhattan, OG online bank.

I’m open to your suggestions. I need help ☹

Please tell me there is still hope for me!