As someone accused of a drug crime, you're in a difficult position. Your future depends very much on how you approach this charge. You shouldn't plead guilty thinking that you'll get a lesser charge if you're not guilty at all, and of course, you need to protect yourself from accusations that are simply off base. With help on your side, you can work with someone who can help you identify any weaknesses in the case against you; with perseverance, you can make your side of the story heard and understood.
In Virginia, you can face a few types of drug charges. You could be charged for possessing drugs, distributing drugs or possessing them with the intent to distribute. The differences between each can be dramatic as far as punishment goes, and the prosecution team may try to make more out of your situation than it really was. For instance, if you were in possession of marijuana and had someone else in your vehicle with you, then you could be accused of possessing it with the intent to distribute it; that's a crime that can be punished more heavily than simple possession.