Absolutely do drill sets and give yourself a bit of an artificial time crunch - when you're working out of a book, it's not actually adaptive, so you can't 100% simulate how hard it is to keep on time during the test.
Are you feeling anxiety over the fact that the clock is ticking down / the section is almost over and then finding it hard to concentrate? Take a look at this:
https://www.manhattanprep.com/gmat/blog ... mat-score/Next:
As a result, I'll attempt problems and give up once I reach the 2:30-3:00 minute mark or guess to try and gain some time.
Sounds like we need to talk about timing / decision-making in general. You should be letting go in that timeframe, so that's good. In fact, how can you identify sooner that some problems just aren't going to happen, so that you don't go over and lose time on that problem? On some problems, you really do know by probably the 1 to 1.5m mark that something's not great about this problem - you're just not acting on it. That's what you need to learn to do .
Read these. Multiple times, probably - keep coming back to them. Think about what you need to do to build these decision-making habits into your standard process for doing a problem.
http://tinyurl.com/executivereasoninghttps://www.manhattanprep.com/gmat/blog ... -the-gmat/http://www.beatthegmat.com/mba/2016/02/ ... n-the-gmatTo develop the 1-minute time sense that those articles discuss:
http://tinyurl.com/GMATTimeManagementTry it out on some individual problems and some problem sets - for a week or two. Then come back here and tell me how it's going.