Hi Saeed,
Don't worry that much, I am sure that you are on the correct track, I personally feel that
you should read the book of Kathy, and do all the mock exams of the Whizlabs simulator. I have seen lot of my students getting good results becuase of these resources. Normally they get the mark which they got for the final exam of the Whizlabs in the real exam. Even I got 48 in the final exam and got 49 in the
SCJP exam. So good luck with for the examination....