To get to the score you are looking to achieve, I think you will need to focus your primary energies on your weak areas. To a certain extent, you have narrowed the field on the Quantative side, but not really on the Verbal side (your weaker portion). Either by reviewing some practice tests or practice problems, you can begin to zero in on the types of problems and/or fundamental concepts that are giving you problems (e.g., Inference questions rather than simply Critical Reasoning, or high level exponents questions).
This is not to say that you should suspend practicing problems in the areas that you feel comfortable with. However, by analyzing not only the types of questions that you got wrong but also the reasons you missed the question (i.e., careless mistake, mis-read the question or did not know how to approach), you can begin to narrow the scope of concepts you need to better understand versus the kinds of questions you need to be more careful on. Remember, that since the GMAT is computer adaptive, making a careless mistake on a problem for which you know how work counts against you as much as missing a problem because you do not understand the concept. Thus, eliminating careless errors helops your score by elevating the "floor" or lower boundary of what you might score.
Once you focus in on the concepts and fundamentals that you need to better understand, go through your resources on those areas and begin to work easy to moderate questions. This will help you to understand how the testmakers "test" these concepts and ensure that you recognize how to approach, set up and work them. This method will also give you more confidence and a comfort level with the problem concepts and this, in turn, will allow you to reduce your stress level while taking the test.
If you have any questions on the specific areas and how best to approach those, or any other questions, please ask.