What more should I do?

I feel so bumbed. I just blew an exam in Med/Surg 1 theory. I studied, studied, studied and thought I knew my stuff, yet my instructor found a way to get me on the wording of the questions. I got a 72% on this exam and an 80% on a quiz we had earlier in the course. I have 2 exams and 1 quiz left to bring my grade up. What worries me is that they will be even harder --fluids/electrolytes, IV therapy and diabetes--you get the picture. What should I do to get a better grade? I am already spending so much time studying. I am so worried.