Hi Danny1994,
With a Score Goal of 550+, you do NOT need to correctly answer ANY questions that you think are too hard or too weird, but you do have to keep the little mistakes to a minimum. Thus, you do NOT need to work on answering anything that you find difficult (and you should actually get in the mindset to quickly "dump" those questions when they appear - so that you have more time to spend on all of the other 'gettable' questions).
Before I can offer you any additional advice for your studies, it would help if you could provide a bit more information on how you've been studying and your goals:
Studies:
1) How long have you studied? How many hours do you typically study each week?
2) What study materials have you used so far?
3) On what dates did you take EACH of your CATs/mocks and how did you score on EACH (including the Quant and Verbal Scaled Scores for EACH)?
Goals:
4) When are you planning to take the GMAT?
5) When are you planning to apply to Business School?
6) What Schools are you planning to apply to?
GMAT assassins aren't born, they're made,
Rich