Unfortunately, the facts you put in your question are "facts." The DUI allegations are set forth in the police report and criminal complaint, and will stand until the case is dismissed or until you receive an entry or not guilty or acquittal from a jury or judge at a bench trial.
If the case was dismissed, it's odd that you have another court appearance. Sounds like you already have a lawyer - so you should really be asking him this question.
Your attorney is in a much better position to discuss your case and answer your questions. I suggest giving them a call and addressing all of your concerns. If you are for some reason unhappy with your attorney, you are certainly free to consider hiring another. Good luck.
If you feel you are not guilty and there is no evidence then tell your attorney that you want a trial. There may be video at the convenience store that could show the actions of you and the officer. The short answer is yes you can still be convicted just from officers testimony if the testimony is believed over your testimony. Your attorney is the best one to answer these questions since he/she has more knowledge of facts and evidence.
"Nothing in this communication is meant to establish an attorney-client relationship. The information is provided for educational purposes only. No action will be taken on your behalf unless you have have hired me and entered into a written retainer agreement. I am only licensed in Tennessee and I suggest contacting an attorney in your specific city and state as soon as possible to avoid any statute of limitations deadlines, if applicable."
Sign up to receive a 3-part series of useful information and legal advice about DUIs.