Improving Verbal as a non-native speaker - 25 days to go

Hi everyone,

I'm looking for advice as I will take my first GMAT exam in 25 days and I am struggeling especially in the verbal section.

Profil:
European (non-native speaker of English language), decent (not a genious though) in maths, usually not too bad in English as I have already spent a year abroad in the US.

I started studying about 6 weeks ago and first went through all Manhattan Quant Guides. I completed all the problem sets and also did every PS/DS question from OG13. Afterwards went through all 3 Manhattan Verbal Guides (RC, CR, SC) and already completed several question from OG13 too. I'm also tracking myself using the OG Navigator. Having finished all 8 books I recently took a GMATPrep and scored 570 (Q44, V25). In order to get into the program I will be applying for I need a score of 640-650 in total.

Quant:
I reviewed the exam afterwards and realized I could have definitly done better in the Quant section (a few stupid mistakes). As mentioned above, right before the GMATPrep I only focused on Verbal so I feel like I can do even a little better (maybe 45-46, as long as the actual test is of same difficulty as GMATPrep) at Quant in 4 weeks if I keep working at my problem areas for 1-2 hours a day and review what I already know.

Verbal:
Obviously my problem area. At the very first day of practise I took a GMATPrep and only finished the Verbal to see where I am - V20. I basically had no idea of how to attack any problem type. Now that I worked through 600 pages of explanations and strategies I felt a lot safer all in all. I understood all the concepts and was correct on pretty much all the problems sets in the Manhattan books and got around 75-80% of OG questions correct. But when I saw the questions on the test the first one was a RC I didn't really understand (made me a lot more uncomfortable right at the beginning) and even afterwards I felt like I couldnt really apply the strategies (e. g. SC) a studied before. That being said I knew my quant result wouldn't be great but a 5 point improvement (V20 -> V25) after finishing all the guides was very demotivating. I felt like I really understood what RC, SC and CR is about before.

I basically have nothing else to do for the next 25 days and I plan to study for about 10-12 hours a day. The only problem I have at the moment is that I am not sure how in order to get the best result on Oct 30. My plan at the moment is to go though my RC, SC and CR summary again and afterwards attack as many OG problems as I can and review the ones I messed up + to focus an hour or two on a specific quant topic each day.

I would really appreciate any comments on my plan, suggestions or similar experiences. Tell me if you guys need to know anything else in order to comment.

THANKS!