I think the most difficult part of the verbal section (aside from SC) is that when you read a passage or a critical reasoning section, there are certain assumptions that you make in your mind, and then when you get to the question, it is difficult to select the right answer if you have made a false assumption. For instance if you read:
"The discontent of the crew eventually led to a mutiny, and the captain was shackled in the hold. The ship returned to shore and the sailors all disappeared into the jungle so they wouldn't have to sail again..."
I realize that's totally random, but follow me here, so after reading a section above, your mind may make certain assumptions like, "These sailors hated their captain," and when you get to the questions, you have these assumptions in mind that affect the answer you choose. But from reading the above, you don't really know that the sailors hated their captain. Maybe they were discontented because there was no food on the ship, and the captain wanted to complete their mission. Even though the crew loved the captain, they simply couldn't continue without food so they captured the captain and went to shore for food. But your mind makes assumptions when you read passages, so it's important to read questions carefully and think about what they're asking, and then go back to the reading passage and look at it totally objectively without any assumptions.
It sounds like your quant score was pretty good and it sounds like you have plenty of room for improvement on the verbal side. So when you attack these verbal questions, really focus on not jumping to conclusions and analyzing as objectively as possible.
If you have
the Official Guide, make sure you spend lots of time going over verbal questions you get wrong, read the answer explanation and really understand why you chose the wrong answer. I don't think a tutor is always necessary, I think you can attack your studying with a more "aware" strategy and really improve your verbal score.