TLDR: What to focus on as a non native with 600 (Q42 and V30) to get up to at least 620 in 8 days?
Hi guys! Just got a quick question concerning my strategy for further studies. Since here are enough GMAT pros around I hope someone will be able to give me some advice

My GMAT is scheduled for May 9th, so I don't have much time left but need some improvement. The good news is that I don't need an astonishingly good overall score, since my bachelor's grade is quite good and the GMAT is not thaat important for admissions over here (Germany). I was aiming for 630 but with 620 I would probably be satisfied as well. The bad news is (like you might have guessed) that I'm not there yet and can't postpone my exam... In the last two weeks I went through all the
MGMAT guides once and solved around 50-100 OG questions verbal and quant each. I took an official GMAT prep test yesterday (600, Q42 V30) and a
MGMAT prep test earlier today (580, Q42 V29). In the quant part my timing was OK and I could have used maybe 3 mins more but in the verbal part the time killed me both times and I had to skip 5-6 questions or so. (Obviously) I'm not a native but I guess my English is not the worst in general (99th percentile on TOEFL, yay

). On RC I just need too long to read and understand the passages, on SC I need too long to understand the differences between the remaining answers after eliminating the really obvious wrong answers through the splits I found correctly, and CR is the only category I'm more or less comfortable with, since the passages are written easier imo.
The big question is: What to focus on from now on? Where do you think the impovment should be easier? Plus for quant: since I don't have the disadvantage of not being native on that part it could be easier to get better fast. Plus for verbal: I feel like I am doing really bad at the moment and because of the diminishing marginal benefit of studying it could be easier to get better fast. What do you guys think?! Every answer is appreciated!

Cheers, Peter