FIrst thing first, the very fact that you've put in "a lot of efforts" doesn't necessarily imply that you'd have prepared the correct way. The fact that you've 50% accuracy on Verbal indicates that your concepts are still not very strong. What has been your strategy while preparing ? Did you ensure that you firstly understand a particular concept say in Sentence correction and then do enough practice problems to test your understanding of those questions?
Did you maintain an error log
? Did you keep on revising the concepts ? Which books did you refer ? Did you participate in discussions with your own study group ?
The answers to all the questions above will help us in finding the right strategy for you.
My 760 debrief