Gestational Diabetes

Hello moms! My glucose screen came back higher than the limit on my initial screen. So of course, this being my first pregnancy I'm panicking! I eat healthy, don't even like sugar. I've avoided all high fructose corn syrup, sodas, any candy (don't like most of it anyways). Can I do anything at this point to prevent it? If so, what? Of course, I am doing the three hour tolerance test tomorrow or Wednesday to more conclusive results.