How concentrated and actively thinking are you when you take the section? Sometimes, some nervousness is necessary to get yourself to go at a great pace. Also, are you solving the questions inefficiently? Maybe you should check the explanations to see whether there are better solutions even to the questions that you are getting right. Recognizing when to (and when not to) plug in answer choices can save a lot of time.
Well, when I do math in general, my brain gets muddled. It's like I can't think straight, which is weird, because in W/CR (especially W) I work very efficiently and solutions are (usually) clear to me immediately. But in math, I do these weird, roundabout paths to solutions and then I realize later that it was actually very simple; I just didn't think it through. So maybe I need to stop and think about the questions beforehand...the way I rush headfirst into every problem may, in fact, be the issue.