GMAT Strategy

Hello, I was wondering if anyone out there could give me tips on how to riase my quant up to the 42-45 range... I have studied for about 1.5 months and Have now taken 4 practice exams 530 Q32 V28, 580 Q37 V30, 550 Q33 V33, and finally last weekend 530 Q33 V31....I have studied daily, but most of it has been "liesure" studying... working problems from the very beginning of OG through entire section, not timed, and rather slow... 40-50 problems over 4-5 hours... I'm wondering what has made others "turn the corner" and really start improving..I'm very poor at not getting distracted while studying, I typically do rather well on my hit rate for the problems out of the OG, ( I have done the entire OG quant supplemental book) and have gotten up to#124 so far on the OG 12th edition...but once I start the practice tests... the 2 min per problem throttles me.... Do a lot of you other test takers constantly do practice under timed condtions? or do you do about half untimed half timed? I'm just trying to find the best angle of attack to improve my quant.. while of course practicing verbal.. (but quant has been by far more frusterating)... Any tips/advice/insight or personal experiences would be great. I have about 2.2 months until my exam yet and plan to keep on keeping on.. but was looking for advice. Thank you.