Don't get bogged down - the only way to a higher score is working hard and working smart.
For starters, try to get rid of your mental block against maths. However hard you work, your mind will subconsciously be less receptive to anything you feel is "difficult". I can only understate how important it is for you take your math exercise in the correct perspective. When you start studying, begin with a good book that walks you through the basic concepts. You might want to try this website: http://www.wtamu.edu/academic/anns/mps/ ... b/gre/ca22
Once you're done with studying and adequately understanding the basic concepts, start with solving basic problems. I recommend you purchase a high-school level text book and work through it.
When done, start off with various GMAT prep aids. Kaplan
is a great bet for math and OG has a great collection. I think you should solve every problem in the OG as it'll only help you get better.
Very important - Do not forget to maintain an error log
of your prep. You will find more information on how to work with error logs and how to derive maximum benefit out of yours on this forum.
Take all your practice tests in a timed environment. This habit will help you build some kind of a "biological timer" which will improve with practice.
I hope you begin your preps at the earliset and give yourself sufficient time before your next take on the GMAT. Here's wishing you all the luck!