As Blue suggested, is it more that you don't understand the material, or that because of curves, the bars are set very high? If it's the later, it's really not that huge of an issue, as the DAT can make up for a low gpa. I applied to dental school with a 3.01 science GPA (C in Ochem 1, D in Ochem 2) and I got in to a number of schools, including Columbia, because I showed that I really did understand the information. This isn't to say it's easy or even common to do what I did, I'm just saying that you shouldn't count yourself out yet.
Seek out help from your professors if you're having issues with the material - right now you think know what you want out of life, now you just need to take hold of that and do what you need to do.