Chemistry :(

Do you have a tutor/study with someone who is doing well in the class? Or can you withdraw and take it next semester if your grade is that close to a 68?

I'd recommend taking up any and all help offered by your institution - do you get Supplemental Instructors? Did you get the solutions manual for your text book? If not, it may be worth getting. Mine didn't have the answers to all of the homework problems (my teacher assigned evens only) but I could work out what to do by looking at the examples for other problems. That's a more efficient way to learn anyway, instead of having the answer handed to you. :) Each chapter was also reviewed really well in outline format which I found easier to read than the text for certain things.