Totally agree w/ ashkrs. I was in the same boat as you about 3months ago.
You have to remember, the majority of the problems on this forum are very difficult. These problems can be real confidence killers since it appears you are very new to the GMAT in general.
I reccomend to use the OG 11
, and the Manhattan GMAT books
Also if your very rusty, as I was, check the internet for basic learning principles such as long division, fractions, decimals, percents, etc...
Your not alone. When I first started I forgot how to do long division, how to turn fractions to decimals, and even forgot how to add fractions.
Check out the books man and def focus on the basics for now.
I also reccomend u stay away from the verbal section too if your having similar problems. Again OG 11
, MGMAT Books
(Especially SC, it is a MUST!!!). CR and RC, not so much, but they did help me.