It is very difficult for non-native speakers. Reading speed is the toughest thing to improve - it can often take 6+ months.
It helps to read every day in English - and not just things for the GMAT. Here are some sources:
http://magazine.uchicago.edu/ - particularly articles in the "Investigations" tab
http://harvardmagazine.com/http://sciam.com/Also, *everyone* struggles with timing on this test, at least a little bit - even native speakers. Part of your task on this test is to recognize when the test has given you something that's too hard, so that you can just let it go fast.
Read this article and start doing what it says:
http://www.manhattangmat.com/blog/index ... anagement/If you can do better with the timing (letting things go sometimes), then that will actually help to take some of the pressure off of the reading speed issue!