Need Some Advice PLEASE

Well 670 is nothing to be ashamed about! that is an excellent score, but I do see that you're shooting for a stellar score. Your math score is pretty solid, but you're going to have to get better in verbal to increase your overall score. Because of the highly competative Quant section and slightly less competative verbal section, your verbal score can seriously drive your total score. So if you could keep your Q the same or slightly higher and bring the verbal up around/over 40, your shot of hitting your goal score is right on track. You are going to have to devote significant study time to your verbal, which can be hard if you excel at math or non native. If you are hoping for a 750, I don't know if I'd dive into a test in the next couple weeks unless your confident in a study plan.

My advice is to make sure to study every question you get wrong in verbal along with ALL the problems you get right. Memorize and learn why the right answer was right, and why all the wrong answers were wrong. You need to start seeing these patterns in problems (just like you already are doing in math). Learn to recognize question types (CR - strenthen, weaken, inference, etc SC - parallelism, modifiers, pronouns, subjust/verb, etc CR - global questions, inference, etc) and common wrong answers (out of scope, 180, etc..) and they go on and on. Just as you do in math, you need to recognize what type of verbal question you are facing, and that will help you attack each question differently and effectively.

In quant, you can do all the work and get the right answer and know you have it right. On the other hand, in verbal it can be just as important seeing which answers are wrong to narrow it down to the right answer. It won't be as clear as in quant. You are close to getting there, you just need to go back to the basics in some of the verbal, and not just go through the motions. Know that you are missing key points, and make sure if you don't know them to continue to study those topics until you have them down.

As far as the high level DS problems are concerned, they can be extremely challenging. Especially since some can be huge time consumers. I would encourage you to not get too caught up over some of the toughest DS problems because on test day those can potentially be a time drain and take you away from questions you could have gotten right at the end of the section. Especially if you get down to tegether or neither on a tough problem, sometimes a guess is best (50/50 isn't bad on a tough problem). It sounds like you know where you are weak in DS problems, so I would work on those types. I've found that with number properties, abs value, and inequality picking numbers can be a great strategy. Practice, and see if it helps. Not only learning how to pick numbers, but picking the right numbers to give you the answers you need will really help.

I made a 140 point increase with about 200 hours of studying, so that's over an hour per point increase. Keep your nose in the books and keep working hard. You are very close, so now you just need to refine you knowledge and strategies. Good luck on G-DAY!