Stoxxyy
I have to admit that I am struggling to find an internship position and sometimes I feel even more frustated, which probably affected the quality of my study time.
When I do questions I review the wrong ones, and more than a half are due to silly mistakes and lack of concentration. I keep an
error log on OG questions and I score about 65-75% in every section except DS.
Yes, sometimes external factors disturb a lot...
What I will suggest is something I did, and since I'm in the beginning of my studies (two months by now) and I'm a non-native speaker too, as yourself, it may help you: Forget about time in the first one/two month (considering you have the 5h/day to study). Just take your time and do the exercises in your pace. You'll maybe spend the 5 hours in the fist week doing 30 exercises daily, but that's OK, because you will be focusing all your concentration and mind into the concepts and nothing will make you get wrong besides the concept itself. Then you will be able to distinguish what you really know (and thus think later about time) and what you need to strengthen (study again, get alternative books, etc). Forget about time and other factors in the beginning - it's a little frustrating, I know, but when you understand the basics, things got easier. Also, sometimes reviewing just the wrong questions isn't the best thing, specially when you have the OG with its nice exercises explanations, which gives you alternative resolutions sometimes or even explains something important that you weren't seeing.
Mastering the basics will give you foundation to preoccupy with time and shortcuts later...
About DS, you may get some tips with the forum's best stories
best-gmat-stories-period-98512.html#p759267