Hi Prateek - Don't worry about your scores for the time being. I have been into this situation and belive me it can really disappointing for anyone after seeing a string of low scores.
Here is what I did to increase my score from 460 to 530 [I am still preparing though]. GMAT is a test which is not all about the prep but also about other factors such as time management skills, your confidence level and of course your prep. I have found the "Confidence Level" the most important factor that can affect the performance on the test.
Now this is what I did to raise my confidence level:
1. Start from Basics. Even if you think that your basics are strong then also I would advise go thorugh the basics. Always remember that unless you answer the easier questions correctly, you will not get questions of higher difficulty and to score higher on GMAT you have to answer the hard questions correctly.
2. Do topic wise prep. Divide both Quant and Verbal Section into sub-sections. For example: Lets say you are doing Quant, so try to do Number properties first and make sure you understand the concept. Utilize GMATClub as much as you can .There are some great people over here who are willing to help as much as you want them to.
3. Use standard material. I think BB has very kindly did an analysis on what material to use. Make sure unless you understand the concept, not to move from that question.
4. Make a study plan and try to stick with that plan. GMAT doesn't need 12 hrs of prep in a day, but make sure you devote deligently 4-5 hours a day if possible.
5. Increasing the score on verbal is difficult than increasing the score on Quant. Please do not take this as a criticism. Score can be increased though, but thorugh very thorough and careful preparation. For example, SC is based on rules, so if you master the rules then you should be fine. The same applies to Question types of CR.
The gist is - DO NOT FEEL DOWN - get on with it with an attitude that this test will not intimidate you this time and you will kill it and you will do fine. Beleive me I may be repeating myself over here, use the experience of people of gmatclub. Its invaluable.
Anything more you want to know please feel to ask.
MGMAT 1 --> 530
MGMAT 2--> 640
MGMAT 3 ---> 610
GMAT ==> 730