Hello Smita,
I understand. It may be overwhelming initially, but you need to go through PMBOK for sure. It may look huge. But once you start reading you will complete it quickly.
I am also preparing for my exam. I will tell how I did/doing it.
Part 1 of PMBOK is most important. Part 2 will just be repetition(in process).
Iteration 1 - I scrolled through pages to get a hold of what I can expect in each knowledge area - Spend an hour
Iteration 2 - Studying topics that I felt that was most interesting. I like mathematics. So I completed all formula related topics.. Ex : EVA, WBS, ES, EF, LS.. LF..., Decision tree analysis, no. of communication channels. standard deviation, three point estimation and PERT estimation. - Maybe 4-5 hours depending on your interest level.
Iteration 3 - Read PMBOK Part 1 completely. No compromise here. Since you would have already covered key areas, it will be easy for you to complete.
Iteration 4 - Take a mock test in simplilearn (free test). The test is easy, but I failed.
Iteration 5 - Start reading as processes (Part 2). Target Initiation and closing. Topics are very less. Less questions but you need to crack almost all to be in target. So make sure you master this.
Iteration 6 - Remaining 3 processes are little forgiving. Meaning you can afford to make some mistakes. Read them again quickly..
Now start appearing for Simulator exams - full 4 hour test. Will test your brain, time management skills, etc. After the test you will get good statistics on where you are lagging behind. Study that. Listen to prepcast videos on that topic. Master the topic and write the next one.
I feel this is working for me. Because we can keep improving. By improving we also gain confidence that we will do better next time.