How hard is GMAT?

The reason the test focuses on math and language is because when you drill down in any subject area these subjects encompass all other areas (science is applied math, sociology is a combination of math though heavily weighted on the communication/critical thinking side, etc.). Both sections are about thinking through problems, be they math or English.

I am wondering if you mean you don't test well in them? You're going to be hard-pressed to score well if those are your weak areas. You should assess your own abilities through a practice test first and then get a sense of where you're at. Once you do that, make a goal for yourself and set aside time to study until you're testing within that range consistently.

This test is HARD. Don't underestimate it.

Kaplan tests are not very representative in my opinion. Think about it this way--their tests are designed to convince you to take their prep course...