You can't shy away from them when you're dealing with math. They'll help you pull up your grade. To memorize chemical reactions, I use index cards. I can take them wherever I go and look at them whenever I have free time. I see a tutor twice a week.
Diagrams are the most important thing.
Do some looking around in the bookstore for good study guides and review books. If you don't read the examples you'll be lost during class. Before a test I practice breathing techniques. If I'm still anxious during a test I chew some gum. It makes me smile.