I would say listen to what people are telling you. But just to offer some other options:
If I were in your shoes and I really didn't stalk this girl (according to the legal definition) and I could prove it. I would be furious at the prosecutor. It appears that he is basically abusing his power in violation of the VI Amendment.
"In all criminal prosecutions, the accused shall enjoy the right to a speedy and public trial, by an impartial jury of the State and district wherein the crime shall have been committed, which district shall have been previously ascertained by law, and to be informed of the nature and cause of the accusation; to be confronted with the witnesses against him; to have compulsory process for obtaining witnesses in his favor, and to have the Assistance of Counsel for his defence."
This may not be in line with your ultimate objective of getting into the Marines, but it may be a good idea to see a lawyer. Possibly sue the state. I would at least see what the legal options were. If the prosecutor is threatening you with prosecution, if you are justified, you should possibly threaten him with a lawsuit.
I know that you are absolutely banned from entering the Navy if you have a pending civil suite, which is why this may not be a viable option for you. But after you get done telling your OSO, I would definately see an attorney. It sounds as though you may already be screwed for the July 8th thing, and you would have to work out all the details.